Using Personal Access Token to access organization repo

I have no problem using a PAT to access my own private repo, but can’t access my organization’s repos (for readonly operations, like fetch) with the same PAT. We don’t use SSO (not on GitHub Enterprise). I can r/w to the organization’s repos using tools like SourceTree (git clients) that use some other form of authentication. What do I need to change to allow me to use a PAT against my org’s repos? Thanks.