Error code 403

One of our employees is getting a "403 Permission_Denied" error message when trying to add her calendar to her Zoom account. She is trying to connect her calendar with the same account that she logs into Zoom with. Right now her calendar is blank in Zoom where there are actual meetings already scheduled.

How can I help her get her calendar added correctly to be able to view on the Zoom Dashboard, I am the Admin on our account.