Can I use an arduino to activate the two on board relays

I am wanting to use this with an arduino to activate the two on board relays. Is that what P5 an P6 are for?? I would like to be able to control the relays manully via a arduino or other micro controler??
thank,

Our onboard ports are for 402u receiver to control other relay boards, not the other way around.

See photo below for clarification.

https://imgur.com/a/eCqggVA

As for P5, P6 they are simple limit switches input to turn off onboard relay, not able to activate (turn on).