It’s a Facebook problem
Nobody can access or post to Facebook Groups any more, because Facebook removed the API option.
You can only do it manually using the app/website.
To resolve this, please contact Facebook to add it back.
For more information, see:
- Send new telegram message for new Facebook group posts
- Facebook Group App is missing?
- Due to the deprecation of the Facebook Groups API, we (Make) will be discontinuing our Facebook Groups app
Hope this helps! Let me know if there are any further questions or issues.
— @samliew