Zoom: how to make someone a co-host
There are two ways that you can make a user a co-host.
During a meeting:Hover over a user's video.
Click the more icon .
Click Make Co-Host.
Using the participants window:Click on Manage Participants in the meeting controls at the bottom of the Zoom window.
Hover over the name of the participant who is going to be a co-host, and choose More.
Click Make Co-Host.
https://support.zoom.us/hc/en-us/articles/206330935-Enabling-and-adding-a-co-host