Unixcop published a tutorial about installing Nessus Scanner on Ubuntu 20.04 and 18.04.

Install Nessus Scanner on Ubuntu 20.04 and 18.04

Nessus is a proprietary vulnerability scanner developed by Tenable, Inc.  It scans cover a wide range of technologies including operating systems, network devices, hypervisors, databases, web servers, and critical infrastructure. Nessus gives you malware detection, scanning of embedded devices, configurations auditing, control systems auditing and compliance checks among other features.

Install Nessus Scanner on Ubuntu 20.04 and 18.04 - Unixcop the Unix / Linux the admins deams