If your shared screen is not showing up in Teams for other participants, here are some things you can do to try and resolve the issue:

1. Check to ensure that the application or window you are sharing has given Teams permission to use it.
2. If you are using an external device such as a laptop, plug it in directly to your computer or try a different USB port.
3. Restart your computer and the Teams application.
4. Check to see if you have the most up-to-date version of Teams running.
5. If you’re still having trouble, you can try using a different app to share your screen such as Zoom, Skype, or Google Hangouts.