What force pushes up on you when you jump vertically off the ground? The force of gravitation, or your feet pushes up, or the ground pushes up on you?
Every action has an equal and opposite reaction. Newton's third Law of motion.)
When you jump vertically, you are pushing on the Earth with a given force. The Earth pushes back with the same force.
Since the mass of the Earth is so great in comparison to your weight, the amount the Earth moves is imperceptable. The amount the Earth moves you is the height of the jump.
So the force is the force exerted by the Earth that is equal in magnitude but opposite in direction to the force you exerted on the Earth.