What RX 3rd party or OEM can i bind with my P4 controller?

[nd34567890]

What 3rd Party or OEM telemetry receiver (RX) can i bind with my P4 controller? I'm soon to build a freestyle quad and don't have the budget to buy a $100-$200+ transmitter, and would like to re-use my DJI P4 controller. Looking for low cost obviously. NOT CONCERNED ABOUT VIDEO (VTX), only control.

thanks in advance,

 

[nd34567890]

I saw Futaba FASST for P1, P2. Anyone with details regarding P4 please?