Mission Planner firmware for FC GOKU GN405 Nano search

I was not able to use BetaFlight with FC GOGKU GN405 Nano , booting and calibration OK ,the Multiplex receiver RX-7 # 5 5818 is not recognized by all serial receiver as SLRX protocol .

Now i wish to use Mission Planner , the mentioned MPX receiver is recognized, but i search the useful firmware for FC GOGKU GN405 Nano.
What solutions with MPX receivers ? thanks