Calendar
The calendar bookings are checked against and written into.
Connected as calendar@example.com
On a real deployment this is where the owner connects their Google Calendar, once. Bookings are then checked against it and written into it with a Meet link.
Other calendars to check
A meeting on another calendar, a personal one for example, can only block a time here if this account can see it. Share that calendar with calendar@example.com as “See only free/busy”, then add its address below. Only busy times are read, never titles or details.
personal@example.com
Checked for busy time