I think I have the same end stop. It should be labeled G S V for the pins. Make sure it's connected like so (however don't take my word for it try and find documentation of both the switch and the board, I don't want to be responsible for a damaged board and I believe you can damage the board if you wire it wrong to the endstop) :
G - Ground
V - Voltage 3.3v Pin
S - Signal
I had to rewire my cable because the pins were not in the same order.
If you have that right you should be able to see the light on the board next to the corresponding motor go on or off if you block the sensor.
Lastly if it's not working you can try to change the endstop modes from S1 to S0 or S0 to S1.
It should not be too difficult as long as the wiring is correct.