'Default access token' doesn't seem to allow link previews at all

[mig5]

Hi

I want to enable link previews in Nextcloud documents for Github issues that are in private repositories.

I don't wish for my Nextcloud users to connect their own Github accounts to their Nextcloud accounts via OAuth.

I created a personal access token (the 'beta' kind, with finely scoped Read-Only access to: code, discussions, issues, metadata, and pull requests

I added that PAT to the global administrative settings in Nextcloud under settings/admin/connected-accounts as the 'Default access token'.

I ticked the box 'Enable Github link previews'

I still get 'Github API error Not Found' widgets appear in my documents when I paste a link to a Github issue in a private repository that this Github user has access to. The widget wants me to go to my personal account settings in Nextcloud to configure Github access, but I thought the 'default' access token should take care of it.

What's the problem? Is it the beta 'fine-grained' PAT method? I don't want to use the Classic method because I don't want Nextcloud to have write access to private repos through this token.

Otherwise, what are the scopes required for the PAT to work, with the beta method?

Do I still have to set up an OAuth2.0 app even though my use case is limited to link previews?

I am running Nextcloud 25.0.8, Github integration app 1.0.15