Thanks, your reciever uses pwm where each channel uses a single wire and nowadays most quads use ppm or SBUS where all channels use a single wire. Read more about that here:
So either you will need to get a ppm/SBUS reciever, there are a bunch compatible with the flysky radio you have. Or you will need to open up your nighthawk and use a cable harness to connect to the FC, but off hand I can’t recall if the FC on the nighthawk supports pwm. But if you need help I can check one we have in stock