Can you provide more detail on connecting to a "private" GitHub repo?

The FAQ says "To accomplish this scenario select generic Git notebook provider (instead of GitHub) and for the password field put fine-grained personal access token which can be generated to have access only to certain repositories."

I created a PAT with EVERY permission within a selected repo, to the fullest-extent allowed by the fine-grained PAT, but still see "An unhandled error occured, please try again" when setting it up within NotesHub.