Last time I checked, there was no read-only permission available for OAuth apps and you were required to create a one-off Github account with limited permissions. https://docs.github.com/en/developers/apps/building-oauth-ap...
[0] https://docs.github.com/en/developers/apps/building-github-a...
[0] https://docs.github.com/en/developers/apps/building-github-a...