Sign in to the Zoom web portal: https://rtmsd-org.zoom.us/
Select Settings.
On right, scroll down to Whiteboard and turn on (blue)
Feel free to turn on "Allow saving of Whiteboard content." This will allow you to save the whiteboard to the computer if you wish
Auto save whiteboard content when sharing is stopped" will automatically save it to your computer.
To enable annotation for your own use:
Sign in to the Zoom web portal.
In the navigation panel, click Settings.
Click the Meeting tab.
Under Meeting (Basic), verify that Annotation is enabled.
If the setting is disabled, click the toggle to enable it. If a verification dialog displays, click Turn On to verify the change.
Note: If the option is grayed out, it has been locked at either the group or account level. You need to contact your Zoom admin.
(Optional) Click the check box to allow saving of shared screens with annotations.
(Optional) Click the check box to restrict annotation to only the user sharing content.