There has been a few people on social media sharing some photos of how they have modded their DJI goggles to mount a fatshark style RX module onto the goggles. One such by TCKFPV nicely shows how simple it is as you just gotta solder power and the video line from one of the PCB inside the goggles:
I will be doing this to my goggles and provide a slightly mode in depth guide if anyone wants to attempt this… although it would undoubtedly void your DJI warranty.