Xbox streaming not working on Xbox Console Companion app on Windows 10.

https://www.xbox.com/en-US/xbox-game-streaming/console-streaming Try that.

Thank you for replying - but that link is for mobile devices specifically, not Windows 10 devices, which is what the OP was asking about.

Currently, the Xbox Console Companion streaming still works on Windows 10. The reason OP was asking about the Xbox app on Windows 10 is because the Xbox Console Companion app is prompting users to install the Xbox app, which does not have streaming support.
I know that there is supposed to be a new Console Streaming app on Windows 10 later this year, but it is not available yet. I was just clarifying that for the OP and anyone else asking the same question about the new app, since I came here with the same question.

You need to stream your console to your laptop (Has to have Windows 10) with The Xbox Console Companion app. Start the Xbox One, then start the Console companion app, then select the connect icon on the left side of the app, and your console should show,
just select it, and select stream, that will then stream your console to your laptop.

Troubleshooting Xbox Console Companion app game streaming on Windows 10:

https://support.xbox.com/en-US/games/troubleshooting/troubleshoot-xbox-app-game-streaming

Console companion app is no longer supported like the rest of Windows 8

You can stream from the Xbox app built into Windows 10 and 11

Hi There,

With windows 10 you can use the Xbox Companion App to stream your console to your PC.