It is slow, requires an Enterprise account, and forces you to manually download massive plugin packs (hundreds of MB) via USB stick. The community calls this "cold" registration.
Note: Download the plugins file. Trying to update plugins offline without this file is very difficult. nessus offline registration hot
This is the core process. Assume you are on a RHEL 9 or Ubuntu 22.04 offline server. It is slow, requires an Enterprise account, and
Open a command prompt and run the command: nessuscli fetch --challenge . It is slow