None of that is necessary. A diode is installed across the relay coil and the input uses an optocoupler to provide either a High or Low input signal to activate.That relay modules has other components on the input coil side of the relay. You will need to trace out the schematic of the input side of the board. We just need to get to the ends of the relay coil. I think there is a diode on the module so we need to know how it is wired.
Les.






