Eventually I discovered Bluetooth Keyboard & Mouse, an app that basically lets you use an Android device as a Bluetooth input device for a PC.

How to Use spacedesk to Mirror or Extend Your PC’s Screen Onto an Android Tablet Before you can mirror or extend your Windows PC’s screen to your Android tablet, you need two things.

Windows 11 now allows the wireless connection of Android smartphones for use as a webcam. We'll show you how to do this and what you should look out for.