If you have ever tried to share e.g. a YouTube video over Teams, you will notice that by default the audio from the application is not shared with attendees. This is easily done, however not obvious where this setting is.
When you are sharing either your desktop or an individual application, move your mouse to the top of the screen (or second screen) and you will see a toolbar appear. Simply click on the Include system audio button to share the audio from that application.
