Air assist- wiring of air pump

I am setting up a new NEJE Max 4 (with extension) and I am totally confused about the wiring for the air assist pump, because I have seen several different variations of it. Could someone please explain how it should be wired and tell me the purpose of the air valve that I have seen pictured and if I need one. My wiring is shown in the attached photo.

The output end is connected to the air pump, the input end is connected to the 12V power supply, and the 2pin port is connected to the M8