I have a monitor with 144hz from Benq (XL2411P) I heard you can play 120hz but I can't
No, that would reach a maximum of 60Hz, with complex games even 30Hz is the end.
If the video you're watching is 120 Hz, then probably? But I don't know if the xbox one s supports hdmi 2.0 at all. And at the same time you would need a monitor to do this. And it won't work in games.