We are unable to access this connected repository on GitHub The authorization key is not valid, or the account used to connect to GitHub doesn't have access to the repository. Try disconnecting the repository above and then reconnect. That is the error I got when trying to connect my private GitHub repo to Heroku.
I've tried doing everything like making it public, or making a new repository, but it just won't work.
I don't have any code to show, since this is a Heroku problem, not a problem with the code.
I don't know what to do.
I have just had and fixed this issue hopefully I can help. Are you setting up a new repository by any chance? What worked for me was to actually add some files the to the repository and push to GitHub, then Heroku was able to read from the repo then. Hope this helps.