I was renewing my GitHub developer tokens so I could use Magit Forge to access issues and pull request when I discovered that the new https://docs.github.com/en/graphql/guides/forming-calls-with-graphql (graphql api for issues and prs, etc). So for now the 'classic' developer tokens are still required. I assume that fine-grained tokens will be supported eventually and I'll update the https://practical.li/spacemacs/source-control/forge-configuration.html when the are.