Never done this before so bear with me.
  1. Create a Canvas, set it to world space.
  2. Add VRC UI Shape, and a box collider with 'Is Trigger' set to true.
  3. Change the layer to something players can collide with.
  4. In game, walk on it as if it were a platform.
Example world here:
You can walk on the eyes and collide with them on open beta, but not on live.
This also happens in my world Terrors of Nowhere where you collide with the game's UI.