Confused By The Unity UI Debug Sample for Oculus Quest

I've stared at this for quite a while and still don't fully understand how it works. I'm looking at the sample UI and trying to create something similar that uses a laser pointer in order to trigger a menu option. When I look at the debug UI demo in unity. Nothing actually shows up and it seems like quest is not even using buttons to define what exists on this canvas. Can anyone shed some light on how this should work/be modified?