A knowledge base article about Why do I see "This meeting is for Authorized Attendees Only" message in Zoom? provided by the UC Berkeley IT Service Hub - Knowledge Portal
If you try to join the meeting or webinar that requires you to be logged into Zoom before joining, and you have not already signed into your Zoom account, you will see the following pop-up message:
"This meeting is for authorized attendees only"
In order to join the meeting, click Sign In to Join, and then sign into your UC Berkeley Zoom account or personal Zoom account in order to join the meeting.