How to make character read a poster in a wall?

Hi, Im trying to make a character face the wall to a poster (texture), push letter "X" and then "read" on the GUI whatever instruction its written there. I am thinking about placing a colider and OnEnter event, fire the GUI. What are the proper steps and code?

Seems like it would make more sense to raycast from the character so you know they are facing the right direction and how far away they are. Are you using the "x" for anything else? You could listen for the letter press, do the raycast, see if what was hit was the poster, and if so, open the GUI. The poster would need to be a separate GameObject with collider so your raycast can hit it.

Are you using javascript or c#?