The key switch is equivalent to a knob that must be inserted with the key. It's the same if you directly connect the wires on the knob with hard wires. Generally speaking, the motor relay has four wires, and the black wire is grounded.
The third line opposite the black line is connected to the key-this line is used to start the motor, and the key is just the connection point of the starting line, which can be started without the key.