This is the snap for nmap.
Nmap ("Network Mapper") is a free and open source utility for network discovery and security auditing.
It works on Ubuntu, Fedora, Debian, and other major Linux distributions.
sudo snap install nmap
That'll install the latest stable release of nmap.
Or, if you're feeling adventurous, try the automatic Launchpad builds published at the edge channel:
sudo snap install nmap --edge
Once installed, this snap needs manually connecting to some plugs:
sudo snap connect nmap:network-control