Getting the normal of a box

I’m currently making a wallrun system and I have problems with the “jumping off wall” function. I check if I’m bedside a wall with a boxcollider and catches the wall actor. So far, so good.
But I need the normal from the box to the player.
Example: the player is running on the right side and wants to jump. It shouldn’t matter where on the right side he jumps, he should still jump 90° from the walls surface.

how do I do this? Or maybe there’s an easier way without the normal? I’m using unreal engine 4.17.2