Sharing your screen
  1. Tap Share in the meeting controls. Green Button with Arrow. 
  2. Tap Screen.
  3. Tap Start Now.
  4. The screen share will start and Zoom will continue to run in the background. ...
  5. At the bottom of your screen, tap Annotate to open the annotation tools or tap Stop Share to stop sharing and go back to meeting controls.


Why can't I share my desktop on Zoom?
In the navigation menu, click Settings. 
Usually found when you click on your face icon found top right in zoom client software 
In the In Meeting (Basic) section, make sure 
Show Zoom windows during screen share is enabled. 
This setting will allow the setting to appear in the desktop client. 
|Sign out of the Zoom desktop client and sign back in.