Using r9mx reciever with pixhawk 4

HOW CAN WE CONNECT AN S PORT F PORT OF FR SKY R9MX RECIEVER TO PIXHAWK 4 FLIGHT CONTROLLER.
Answer with explanation

you must use any uart port of your flight controller.
if i remember well you must use only the TX pin of the uart port.
Check also if your module have the inverted bus or nit coz f7 no need it