What is the correct way for conditional redirect?

[moutasem1989]

Using Authentik as a proxy authenticator for a services, I would like to redirect after authentication based on a variable.

In my case, the proxy authentication is initiated under subfolder /ssoauth. The value then is called as follows:

location /ssoauth {
    [related to Authentik]

    ##here I set the value using auth_request_set
    auth_request_set $authentik_authuri $upstream_http_x_auth_uri;

    ##i check if the value is correctly set. The url is correctly formed and usable
    add_header X-Debug-Auth-URI $scheme://$host$authentik_authuri;

    ##i am trying to check if the value is set before redirecting. Sadly the redirecting is not initiated.
    if ($authentik_authuri != "") {
        return 302 $scheme://$host$authentik_authuri;
    }
    proxy_pass  $forward_scheme://$server:$port/;
}

How can I correctly redirect to $scheme://$host$authentik_authuri when $authentik_authuri is set by auth_request_set?

[moutasem1989]

This was answered here:
https://stackoverflow.com/questions/79481718/nginx-redirect-to-variable-value-with-out-by-passing-proxy-authentication/79482346#79482346