Yup, here's how I do it. Works for remote PC to PC to XBox or Mobile to PC to XBox.
If you have a computer with Chrome and Windows 10 on the same network, you can do everything on an Android device.
1] Install Chrome Remote Desktop on your computer, and the app on your mobile. Pair them.
2] Install UCR on your computer - this will let you simulate an controller
3] Install the vJoy driver - this adds XBox controllers to the UCR database
4] Set up controls mapped to keyboard [for Rewards app, you just need Up, Down, Left, Right, A, and B - I used W, S, A, D, J, and L, respectively] Here's a tutorial.
5] Now that you have mobile remote in and a virtual controller, you just need to launch the XBox Console Companion App and go over to the second to last icon on the left hand menu, titled "Connection".
6] Make sure your console is linked to the app, and stream. If your UCR is properly set up, you should have control of the XBox via your mobile keyboard. If not, you'll see a message that says "No controller detected".
7] Profit!