Generate a "Challenge Code" from the offline Nessus scanner using the command line ( nessuscli fetch --challenge ).
If you want, I can:
As of the last published pricing, a Nessus Professional license typically costs around $3,000 to $4,000 USD per year per scanner. While this is significant for an individual, it is standard for enterprise-grade security tools. nessus professional license key
Let's be blunt:
Once a valid license key is applied, several professional-grade features become available: Generate a "Challenge Code" from the offline Nessus