If you are a moderator in an E-meet you can start/stop an E-meet and control who is broadcasted at each moment, to share somebody's desktop etc .
In this resource:
To start an e-meet, click on 'Open E-meeting controls' and toggle 'Start E-meeting'.
To start to stream yourself, click on your profile under category 'Moderators'. Click on the broadcast icon.
When a participant requests to speak, the moderators will get a notification, and the participant will appear at the top of the list under 'Participants'. Click on the participant to open controls, click on the broadcast icon to start streaming the participant.