Player going through objects issue

I’ve currently been trying to find out why my player keeps going though my imported model. I’ve tried applying a mesh collider to both the stairs and the player model, yet to no avail unfortunately. If anyone can please tell my why there might still be an issue that would help me out so much right now.

MeshColliders can’t collide with each other, so make sure your player has some other form of collider like capsule collider or character controller