Participants enter zoom room before host opens room

[LauraRUK]

I have scheduled zoom meetings.  However, participants can enter the room without me, the host, starting the meeting.  I looked through all the settings and do not see where I can be the only one to start the meeting.  I've entered the zoom meeting about 20 minutes before the scheduled time to set up and

[Ray_Harwood]

Welcome to the Zoom Community, @LauraRUK.

This is enabled by this check-box on the meeting settings: