- Edited
You'll have to use these settings which are found in your kinematic/rigid/static etc body settings
The layer matrix indicates in what layer the selected body is, while the mask matrix indicates with what other layers the body will detect collisions with
So you just need to have your ground be a layer and then select that layer in the payer's mask matrix
Also do the same in the grounds properties i.e. select the player's layer in the grounds mask property
https://docs.godotengine.org/en/3.2/tutorials/physics/physics_introduction.html#collision-layers-and-masks
This link will be helpful for you