How do stairs work?

I’ve looked under the platformer template for example, and noticed the “bot” doesn’t have any rigid body setup. That, and the red stairs there are definitely not one perfect slope mesh, and indeed have gaps. So what exactly is letting the character actually climb up them?

I’ve been trying to get a player in first person view to move up a steep, blocky staircase, but haven’t been able to wrap my head around it. I thought at first NavMesh might be useful, but its only pathing?

Closest thread I could find for help was this one: