I posted a self Q&A on Stack Overflow:  
[Re-enable GitHub two-factor authentication with Authenticator app when switching to a new smartphone](https://stackoverflow.com/questions/77693912/re-enable-github-two-factor-authentication-with-authenticator-app-when-switching). 

It got closed because *"This question does not appear to be about a specific programming problem, a software algorithm, or software tools primarily used by programmers."*

What is the best Stack Exchange site for this self Q&A?