Click on 'Join call' to activate Screenshare.
There are two ways to share your screen:
This allows you to display your screen, and by clicking on the screenshare option as illustrated below.
Your screen can be viewed by the participants in the space, as shown below.
By clicking on the rectangular screen displayed above, it will expand as demonstrated below.
Screen share - expanded
You can add this element by clicking on '+' and selecting 'Screenshare' element.
This will provide a plane which you can use to share your screen with other participants in the same experience.
3D Screenshare element
Using the right panel, you can modify the screen's dimensions, size, proportion, and transparency.
Right Panel - Screenshare