Continuing this I thought to buy this switch:
https://www.amazon.co.uk/gp/product/B07D5ZZ7GY/ref=ox_sc_act_title_1?smid=A3DBEDBOSLQ3Z&th=1
It has a clear wiring diagram and I think if I'll connect the constatnly the green and the black together from the controller side, and then let them...