The Skype Team has brought screen sharing to Skype for Web.
During Skype call, with this support, you will be able to show a PowerPoint presentation to your co-worker or even do online shopping with your close friend. Simply tap on … during a Skype call and select Share Screen to get started.
Currently available in preview in version 18.104.22.168, the new feature means users no longer need extensions or plugins. It does, however, require the use of Chrome 72 or above (and presumably in the future the Chromium-powered Edge browser).
To test the feature login to Skype for Web at preview.web.skype.com.