The “issues: write” permission seems to allow commenting on issues, but not on pull requests. This is unusual, since generally pull requests are treated as a special case of issues.
That’s expected since issues and pull requests have separate permissions in GitHub Apps. GitHub Apss have more granular permissions than the scope-based permissions that were available before. See
and the notes at the end of the page.
However, even after enabling the pull requests read/write permission, the create a comment1 endpoint appears not to work – I get a 403 error. Is there another endpoint for creating issue comments (not comments on a diff) for PRs?
Can you share the full output of a curl -v request which clearly demonstrates this behavior? Just mask the token you used for the request in the output of curl -v. That output should help us investigate and offer advice.