When using the OAuth REST API endpoint: https://api.atlassian.com/oauth/token/accessible-resources the response will send all available resources to the user that approves the app calling the endpoint, and then the Site ID in that body will be used to call the product API on behalf of the user.

If you try to run the endpoint https://api.atlassian.com/oauth/token/accessible-resources and authorize the app as a guest, the API won't return a list of any available resources.

This prevents third-party apps from allowing Confluence Guests to complete the app authorization flow.

It would be great if the endpoint https://api.atlassian.com/oauth/token/accessible-resources could check and retrieve accessible resources for Confluence guests.

Endpoint reference: https://developer.atlassian.com/cloud/confluence/oauth-2-3lo-apps/#get-list-of-resources