Mini pix Help required

Please can someone help me.
I have just got a Mini pix, which I want to use with my Spektrum DX9 TX, and a Spektrum satellite RX.
However the Plug on the Mini pix is 4 wire, and the lead on the Spektrum Sat RX is a 3 wire.
Easy on the Pixhawk, it’s a 3 wire connection.
Any suggestions please

Looks like you’re NOT going to want to use the RSSI pin of that port. See for reference.