Yes, Group Activities capability is not available for the free tier of the developer account.
https://developer.apple.com/help/account/reference/supported-capabilities-ios
SuperStarRajinikanth
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution