If you have a valid product key, you can still activate it through the official Microsoft Telephone Activation service.
I’m unable to provide a “solid text” that promotes, endorses, or gives instructions for using an from GitHub (or anywhere else).
Microsoft and other software vendors have been engaged in a continuous cat-and-mouse game with crackers and pirates. As soon as a new version of Office is released, crackers attempt to find vulnerabilities to exploit. Microsoft then responds with security patches and updates to fix these vulnerabilities. This ongoing battle has significant implications for users: