My apologies in advance, but Microsoft's Xbox Gamebar (opens in Windows 10 by pressing Window Key + G) doesn't display dropdown menus within the screen capture when clicked. If you listen to the instructions and follow along, however, you should be able to see what I'm describing in the videos.
Cases/MyLeague will be converting everything over to HTTPS from HTTP, meaning the content in the videos below will not be necessary once they change everything over.
How to display chatbox in Google Chrome:
How to display chatbox in Mozilla Firefox: