Installing a rogue local Network License Manager (NLM) that mimics an enterprise-level FlexLM server.

The internet connection requirement in Revit 2021 serves legitimate purposes: protecting intellectual property, ensuring users receive updates and support, and enabling valuable cloud-based features. Working within this system, rather than against it, provides the best possible Revit experience—secure, supported, and fully functional.

If you need help exploring compliant software options, please let me know: