When you integrate your eclipse project with a github repository you can use a personal access token (PAT) to authorize the integration and let eclipse write to and read from github. Unless the PAT is set to never expire, eventually you will need to create a new PAT. The github side was easy because I got an email that said it was expired and gave me a link to extend it.
The question then is ... where do I go in Eclipse to put the new PAT? It has been a while since I set it up in the first place.
It turned out to be relatively easy too.
When you do an operation, such as commit, Eclipse will pop up a dialog box where you can enter your github user name and password ... you put the new PAT in for your password. Checking the box for "Store in Secure Store" let's eclipse remember the PAT without you needing to manually copy/paste it in each time.
Example: Right click on the project > Team > Commit...