what is the best way to get OSD on a fixed wing aircraft with out a flight controller

I am interested in the answer as well

I think, without FC you are not able to see OSD. OSD is shown by UART Tx and Rx and there are data for OSD. This only works with betaflight firmware, no OSD data with iNAV. iNAV is better for fixed wing. Now I will test Matek F722 wing with FPV Air Unit and Betaflight firmware.