Zoom will be automatically assigning waiting rooms to any meeting that is created without a passcode. Passcodes are on for all meetings by default, but if you have opted out of this in your settings, your attendees will need to be admitted into meetings by a host or co-host beginning on Sunday, September 27, 2020. Attendees will not hear or see anything in the meeting until they are admitted.
Zoom has improved the Waiting Room notifications so the meeting host will now receive a visual and auditory notification that an attendee has entered the Waiting Room. Additional details on this change are available on Zoom's FAQ Meetings Waiting Room and Passcode Requirements page.
To admit attendees, the host or co-host should click Manage Participants, then click Admit for an individual user or select Admit All at the top of the list.