If you skipped past this at the time, you can go back and enable it - simply select 'Security Settings' in the left hand menu within the App, and toggle to. By default, the Zoom window is not shared while sharing your screen. Showing Zoom windows during screen share.

End Meeting: Leave the meeting or end the meeting for all participants. Note: Do not enable this setting if you are not sharing a full screen video clip, as it will blur your screen share.