I can't figure out how to check if a RigidBody is on the floor for jumping

I’m very new to coding and I can’t figure out how to check if a player(rigidbody) is colliding with the floor plane or other objects. the only way i could find online was using the Player movement template. The “is_on_floor” function also doesn’t work for some reason. Any help would be greatly appreciated.

I’m trying to figure it out right now for my project and just wanted to tell you is_on_floor() doesn’t work for RigidBody2D and 3D, it only works for CharacterBody2D and 3D