Once you activate screen-share, you will get a pop-up screen as follows, which will give you options to share either a specific screen or all available as per image attached. Select the desired choice and click on "share" button.
You can do the screen sharing by clicking on ‘Screen share’ button available at the top of your tool bar. [If you are doing the screen sharing for the first time, system will automatically take you to the pop-up window where in you need to enable the ...