I found it. Hover over the 3 lines in the top LEFT corner (the web instructions say something about a hamburger in the top right corner.....)

The Windows 10/11 app and the XBox app has a new Settings menu option "Speaker Configuration". This replaces the "Use AC3 passthrough when possible" option. Our apps on other platforms will get this option soon.

"Stereo Speakers" - for the TV built-in speakers or any configuration where you have ...