I do not know how to connect the ground wire.
Loosen the screw with a screwdriver, clamp the grounding wire in the metal fittings, and close the screws again.
※If you can not lift the cover (cover), please insert a flathead screwdriver and open it.
One touch operation
Lift the lid more than 90 degrees while inserting the ground wire in the insertion slot and return the lid to its original position, it will be fixed.