[Bug]: Inventory 'netbox_inventory.yml' parsing fails in Ubuntu 22.04 LTS to Netbox!!!!

[ScorpionKing34]

Ansible NetBox Collection version

v3.15.0

Ansible version

/opt/netbox$ ansible --version

" ansible [core 2.15.6]
config file = /opt/netbox/ansible.cfg
configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
ansible python module location = /usr/lib/python3/dist-packages/ansible
ansible collection location = /opt/netbox/collections
executable location = /usr/bin/ansible
python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
jinja version = 3.0.3
libyaml = True"

/opt/netbox$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.1 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

NetBox version

v3.6.5

Python version

3.10

Steps to Reproduce

I don't show the full IP.

Create the following ansible.cfg in main directory of the netbox project direcory. Here are the content:

[defaults]
collections_paths = ./collections
host_key_checking = false
inventory = ./inventory/netbox_inventory.yml
timeout = 120
nocows = 1
retry_files_enabled = False

[inventory]
cache = false
enable_plugins = netbox, ini

[inventory_plugins]
use_extra_vars = false 

Then I created the netbox_inventory.yml under directory 'inventory'. here by the content of netbox_inventory.yml:

---
plugin: netbox.netbox.nb_inventory
api_endpoint: http://192.168.XXX.XX:8000
token: *************Netbox*API*******************************           
validate_certs: True
config_context: False
interfaces: True

$ ansible-galaxy collection list

# /usr/lib/python3/dist-packages/ansible_collections
Collection                       Version
netbox.netbox                 3.15.0

$ pip3 list

Package                     Version
---------------------- ---------------
pytz                            2022.1
pynetbox                    7.2.0
packaging                   21.3

Expected Behavior

Working dynamic inventory from my netbox server 192.168.XXX.XX (I do not show my full IP)

Observed Behavior

When I ran the following command I got this error:
/opt/netbox$ ansible-inventory -v --list

Using /opt/netbox/ansible.cfg as config file
Fetching: http://192.168.XXX.XX:8000/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory plugin: expected
string or bytes-like object
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern '---' supplied, '---' is normally a sign this is a
YAML file.
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

Deeper verbose information:
/opt/netbox$ ansible-inventory -vv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Fetching: http://192.168.XXX.XX:8000/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory plugin: expected
string or bytes-like object
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern '---' supplied, '---' is normally a sign this is a
YAML file.
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

/opt/netbox$ ansible-inventory -vvv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Fetching: http://192.168.XXX.XX:8000/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory plugin: expected
string or bytes-like object
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 2060, in parse
    self.main()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1907, in main
    self.fetch_api_docs()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1513, in fetch_api_docs
    if version.parse(netbox_api_version) >= version.parse("3.5.0"):
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 49, in parse
    return Version(version)
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 264, in __init__
    match = self._regex.search(version)
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern '---' supplied, '---' is normally a sign this is a
YAML file.
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible/plugins/inventory/ini.py", line 137, in parse
    raise AnsibleParserError(e)
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

/opt/netbox$ ansible-inventory -vvvv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
setting up inventory plugins
Loading collection ansible.builtin from 
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Loading collection netbox.netbox from /usr/lib/python3/dist-packages/ansible_collections/netbox/netbox
Fetching: http://192.168.XXX.XX:8000/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory plugin: expected
string or bytes-like object
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 2060, in parse
    self.main()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1907, in main
    self.fetch_api_docs()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1513, in fetch_api_docs
    if version.parse(netbox_api_version) >= version.parse("3.5.0"):
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 49, in parse
    return Version(version)
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 264, in __init__
    match = self._regex.search(version)
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern '---' supplied, '---' is normally a sign this is a
YAML file.
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible/plugins/inventory/ini.py", line 137, in parse
    raise AnsibleParserError(e)
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

Can any help to get ansible working with netbox or fix this bug.
If you need additional information, please contact me.

UPDATE 3-12-23

Tried also the following:
/opt/netbox$ export NETBOX_TOKEN=Netbox_API******************
/opt/netbox$ export NETBOX_API=http://192.168.XXX.XX:8000/

Update the 'netbox_inventory.yml':

plugin: netbox.netbox.nb_inventory
api_endpoint: http://192.168.XXX.XX:8000/
token: "{{ lookup('env', 'NETBOX_API_TOKEN') }}"
validate_certs: True
config_context: False
interfaces: True

/opt/netbox$ ansible-inventory -vvvv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
setting up inventory plugins
Loading collection ansible.builtin from 
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Loading collection netbox.netbox from /usr/lib/python3/dist-packages/ansible_collections/netbox/netbox
Fetching: http://192.168.XXX.XX:8000/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory
plugin: expected string or bytes-like object
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 2060, in parse
    self.main()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1907, in main
    self.fetch_api_docs()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1513, in fetch_api_docs
    if version.parse(netbox_api_version) >= version.parse("3.5.0"):
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 49, in parse
    return Version(version)
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 264, in __init__
    match = self._regex.search(version)
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern 'plugin:' supplied, ending in
':' is not allowed, this character is reserved to provide a port.
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible/plugins/inventory/ini.py", line 137, in parse
    raise AnsibleParserError(e)
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

And with '---' one line one:

---
plugin: netbox.netbox.nb_inventory
api_endpoint: http://192.168.180.85:8000/
token: "{{ lookup('env', 'NETBOX_API_TOKEN') }}"
validate_certs: True
config_context: False
interfaces: True

/opt/netbox$ ansible-inventory -vvvv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
setting up inventory plugins
Loading collection ansible.builtin from 
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Loading collection netbox.netbox from /usr/lib/python3/dist-packages/ansible_collections/netbox/netbox
Fetching: http://192.168.XXX.XX:8000/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory
plugin: expected string or bytes-like object
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 2060, in parse
    self.main()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1907, in main
    self.fetch_api_docs()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1513, in fetch_api_docs
    if version.parse(netbox_api_version) >= version.parse("3.5.0"):
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 49, in parse
    return Version(version)
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 264, in __init__
    match = self._regex.search(version)
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern '---' supplied, '---' is
normally a sign this is a YAML file.
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible/plugins/inventory/ini.py", line 137, in parse
    raise AnsibleParserError(e)
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

[sc68cal]

What is returned when you do an HTTP GET to http://192.168.XXX.XX:8000/api/status

[sc68cal]

Can you try applying #1111 ?

[ScorpionKing34]

Command on Netbox server:
netbox$ sudo ufw status

[sudo] password for REDACTED:
Status: active

To                         Action      From
--                         ------      ----
OpenSSH                    ALLOW       Anywhere
80/tcp                     ALLOW       Anywhere
443                        ALLOW       Anywhere
8000                       ALLOW       Anywhere
OpenSSH (v6)               ALLOW       Anywhere (v6)
80/tcp (v6)                ALLOW       Anywhere (v6)
443 (v6)                   ALLOW       Anywhere (v6)
8000 (v6)                  ALLOW       Anywhere (v6)

Command on Ubuntu desktop:
ubbuntu:/opt/netbox$ curl -v http://192.168.XXX.XX:8000/api/status -H "Authorization: Token REDACTED"

*   Trying 192.168.XXX.XX:8000...
* connect to 192.168.XXX.XX port 8000 failed: Connection refused
* Failed to connect to 192.168.XXX.XX port 8000 after 1 ms: Connection refused
* Closing connection 0
curl: (7) Failed to connect to 192.168.XXX.XX port 8000 after 1 ms: Connection refused

Command on Kali box:
nmap to Netbox:
$ nmap -sT -sV -Pn -p- 192.168.XXX.XX

Host is up (0.0014s latency).
Not shown: 65531 filtered tcp ports (no-response)
PORT     STATE  SERVICE  VERSION
22/tcp   open   ssh      OpenSSH 8.9p1 Ubuntu 3ubuntu0.4 (Ubuntu Linux; protocol 2.0)
80/tcp   open   http     Apache httpd 2.4.52
443/tcp  open   ssl/http Apache httpd 2.4.52
8000/tcp closed http-alt
Service Info: Hosts: 192.168.180.85, netbox.example.com; OS: Linux; CPE: cpe:/o:linux:linux_kernel

It shows port 8000 is closed but on Netbox is open:

https://nmap.org/book/man-port-scanning-basics.html

closed

A closed port is accessible (it receives and responds to Nmap probe packets), but there is no application listening on it. They can be helpful in showing that a host is up on an IP address (host discovery, or ping scanning), and as part of OS detection. Because closed ports are reachable, it may be worth scanning later in case some open up. Administrators may want to consider blocking such ports with a firewall. Then they would appear in the filtered state, discussed next. 

I followed the installation from 'https://netboxlabs.com/blog/getting-started-with-network-automation-netbox-ansible/'

Command on Netbox server:
netbox$ curl -v -k -H "Authorization: Token REDACTED" https://127.0.0.1/api/status/

*   Trying 127.0.0.1:443...
* Connected to 127.0.0.1 (127.0.0.1) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* TLSv1.0 (OUT), TLS header, Certificate Status (22):
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS header, Finished (20):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.2 (OUT), TLS header, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN, server accepted to use http/1.1
* Server certificate:
*  subject: C=NL; ST=REDACTED; L=REDACTED; O=REDACTED; OU=REDACTED; CN=REDACTED; emailAddress=netbox@testing.nl
*  start date: Nov 21 22:58:28 2023 GMT
*  expire date: Nov 20 22:58:28 2024 GMT
*  issuer: C=NL; ST=REDACTED; L=REDACTED; O=TESTING; OU=REDACTED; CN=netbox; emailAddress=netbox@testing.nl
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
> GET /api/status/ HTTP/1.1
> Host: 127.0.0.1
> User-Agent: curl/7.81.0
> Accept: */*
> Authorization: Token REDACTED
>
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* old SSL session ID is stale, removing
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Mark bundle as not supporting multiuse
< HTTP/1.1 400 Bad Request
< Date: Sun, 03 Dec 2023 17:46:33 GMT
< Server: gunicorn
< Content-Type: text/html; charset=utf-8
< Vary: origin
< Connection: close
< Transfer-Encoding: chunked
<
* TLSv1.2 (IN), TLS header, Supplemental data (23):

<!doctype html>
<html lang="en">
<head>
  <title>Bad Request (400)</title>
</head>
<body>
  <h1>Bad Request (400)</h1><p></p>
</body>
</html>
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Closing connection 0
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
* TLSv1.3 (OUT), TLS alert, close notify (256):

Commands on Ubuntu box:
ubuntu:/opt/netbox$ curl -v -k -H "Authorization: Token REDACTED" https://192.168.XXX.XX/api/status/

*   Trying 192.168.XXX.XX:443...
* Connected to 192.168.XXX.XX (192.168.XXX.XX) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* TLSv1.0 (OUT), TLS header, Certificate Status (22):
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS header, Certificate Status (22):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS header, Finished (20):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Encrypted Extensions (8):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, CERT verify (15):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Finished (20):
* TLSv1.2 (OUT), TLS header, Finished (20):
* TLSv1.3 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
* TLSv1.3 (OUT), TLS handshake, Finished (20):
* SSL connection using TLSv1.3 / TLS_AES_256_GCM_SHA384
* ALPN, server accepted to use http/1.1
* Server certificate:
*  subject: C=NL; ST=REDACTED; L=REDACTED; O=REDACTED; OU=REDACTED; CN=netbox; emailAddress=netbox@testing.nl
*  start date: Nov 21 22:58:28 2023 GMT
*  expire date: Nov 20 22:58:28 2024 GMT
*  issuer: C=NL; ST=REDACTED; L=REDACTED; O=REDACTED; OU=REDACTED; CN=netbox; emailAddress=netbox@testing.nl
*  SSL certificate verify result: self-signed certificate (18), continuing anyway.
* TLSv1.2 (OUT), TLS header, Supplemental data (23):
> GET /api/status/ HTTP/1.1
> Host: 192.168.XXX.XX
> User-Agent: curl/7.81.0
> Accept: */*
> Authorization: Token REDACTED
> 
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* old SSL session ID is stale, removing
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Date: Sun, 03 Dec 2023 17:56:39 GMT
< Server: gunicorn
< Content-Type: application/json
< Vary: HX-Request,Cookie,origin
< Allow: GET, HEAD, OPTIONS
< X-Request-ID: f0a941bd-a3c9-4c63-b77f-b762c6f1ecf1
< X-Content-Type-Options: nosniff
< Referrer-Policy: same-origin
< Cross-Origin-Opener-Policy: same-origin
< X-Frame-Options: SAMEORIGIN
< Content-Length: 486
< 
* TLSv1.2 (IN), TLS header, Supplemental data (23):
* Connection #0 to host 192.168.XXX.XX left intact
{"django-version":"4.2.7","installed-apps":{"debug_toolbar":"4.2.0","django_filters":"23.3","django_prometheus":"2.3.1","django_rq":"2.8.1","django_tables2":"2.6.0","drf_spectacular":"0.26.5","drf_spectacular_sidecar":"2023.10.1","graphene_django":"3.0.0","graphiql_debug_toolbar":"0.2.0","mptt":"0.14.0","rest_framework":"3.14.0","social_django":"5.4.0","taggit":"4.0.0","timezone_field":"6.0.1"},"netbox-version":"3.6.5","plugins":{},"python-version":"3.10.12","rq-workers-running":1}

ubuntu:/opt/netbox$ curl -v -k -H "Authorization: Token REDACTED" https://192.168.XXX.XX:8000/api/status/

*   Trying 192.168.XXX.XX:8000...
* connect to 192.168.XXX.XX port 8000 failed: Connection refused
* Failed to connect to 192.168.XXX.XX port 8000 after 2 ms: Connection refused
* Closing connection 0
curl: (7) Failed to connect to 192.168.XXX.XX port 8000 after 2 ms: Connection refused

Based on this I tried the following formats on the netbox_inventory.yml:

Option 1#

plugin: netbox.netbox.nb_inventory
api_endpoint: "https://192.168.XXX.XX/"
token: "REDACTED"
validate_certs: True
config_context: False
interfaces: True

ubuntu:/opt/netbox$ ansible-inventory -vvvv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
setting up inventory plugins
Loading collection ansible.builtin from 
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Loading collection netbox.netbox from /usr/lib/python3/dist-packages/ansible_collections/netbox/netbox
Fetching: https://192.168.XXX.XX/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory
plugin: expected string or bytes-like object
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 2060, in parse
    self.main()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1907, in main
    self.fetch_api_docs()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1513, in fetch_api_docs
    if version.parse(netbox_api_version) >= version.parse("3.5.0"):
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 49, in parse
    return Version(version)
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 264, in __init__
    match = self._regex.search(version)
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern '---' supplied, '---' is
normally a sign this is a YAML file.
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible/plugins/inventory/ini.py", line 137, in parse
    raise AnsibleParserError(e)
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

Option 2#

:/opt/netbox$ export NETBOX_TOKEN=REDACTED

plugin: netbox.netbox.nb_inventory
api_endpoint: "https://192.168.XXX.XX/" 
token: "{{ lookup('env', 'NETBOX_TOKEN') }}"
validate_certs: True
config_context: False
interfaces: True

:/opt/netbox$ ansible-inventory -vvvv --list

ansible-inventory [core 2.15.6]
  config file = /opt/netbox/ansible.cfg
  configured module search path = ['/home/bc-dev01/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3/dist-packages/ansible
  ansible collection location = /opt/netbox/collections
  executable location = /usr/bin/ansible-inventory
  python version = 3.10.12 (main, Nov 20 2023, 15:14:05) [GCC 11.4.0] (/usr/bin/python3)
  jinja version = 3.0.3
  libyaml = True
Using /opt/netbox/ansible.cfg as config file
setting up inventory plugins
Loading collection ansible.builtin from 
redirecting (type: inventory) ansible.builtin.netbox to netbox.netbox.nb_inventory
Loading collection netbox.netbox from /usr/lib/python3/dist-packages/ansible_collections/netbox/netbox
Fetching: https://192.168.XXX.XX/api/status
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ansible_collections.netbox.netbox.plugins.inventory.nb_inventory
plugin: expected string or bytes-like object
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 2060, in parse
    self.main()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1907, in main
    self.fetch_api_docs()
  File "/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox/plugins/inventory/nb_inventory.py", line 1513, in fetch_api_docs
    if version.parse(netbox_api_version) >= version.parse("3.5.0"):
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 49, in parse
    return Version(version)
  File "/usr/lib/python3/dist-packages/packaging/version.py", line 264, in __init__
    match = self._regex.search(version)
[WARNING]:  * Failed to parse /opt/netbox/inventory/netbox_inventory.yml with ini plugin: Invalid host pattern 'plugin:' supplied, ending in
':' is not allowed, this character is reserved to provide a port.
  File "/usr/lib/python3/dist-packages/ansible/inventory/manager.py", line 293, in parse_source
    plugin.parse(self._inventory, self._loader, source, cache=cache)
  File "/usr/lib/python3/dist-packages/ansible/plugins/inventory/ini.py", line 137, in parse
    raise AnsibleParserError(e)
[WARNING]: Unable to parse /opt/netbox/inventory/netbox_inventory.yml as an inventory source
[WARNING]: No inventory was parsed, only implicit localhost is available
{
    "_meta": {
        "hostvars": {}
    },
    "all": {
        "children": [
            "ungrouped"
        ]
    }
}

And what do you mean by ''Can you try applying #1111 ?' ?

also what is see is that it loads the following collection '/usr/lib/python3/dist-packages/ansible_collections/netbox/netbox', but I have defined 'ansible collection location = /opt/netbox/collections'

Any suggestions?