Are GitHub Docs Useless for PATS/Personal Access Tokens and the CLI?

After a rough couple years I saddled up and got back on the GitHub horse, but discovered the world of Personal Access Tokens or PATs. I muddled my way through it a few months ago (am a mediocre git person and only use the CLI; am open to IDEs you like if they will help me).

A couple days ago that PAT expired. My first problem is that AFAIK error messages just tell you things are failing, not that the reason why is the PAT expiration.

I am in some kind of special hell trying to revive my repo. I will cheerfully admit I just started trying random things, like using stack overflow answers I didn't understand. Now my repo is in accessible. You may say it's my fault for being a doofus, and I won't disagree. Obvious point here is to RTFM.

But I can't find overview material on the PATs at either https://git-scm.com/doc or https://docs.github.com/en/get-started. Certainly not how they interact with error messages or the CLI. If there is some kind of friendly summary of how PATs work it's passed me by.

Is this stuff wildely underdocumented or am I just suffering from burnout? If the answer is RTFM by all means, point me there.