Ok, so after a bit of digging and testing(like 10-20 minutes) i found out that you need to use the get_popup
method and connect the id_pressed
signal from that popup that you got, aka like this:
get_popup().connect("id_pressed",self,"func_name")
and the function is set like this:
func func_name( ID ):
# Some Beautiful Code Here <3
and ID
is the number of the item that was selected...
hope i helped this time was fun exploring it tho