Based on the above pinout sourced from the depths of the interwebs the audio cable to Digirig should look like this:
Pin #11 RX Audio → 3.5mm TRRS tip (RIG_AFOUT)
Pin #23 Mic Audio → 3.5mm TRRS ring 1 (RIG_AFIN)
Pin #21 Mic PTT → 3.5mm TRRS ring 2 (RIG_PTT)
Pin #10 GND → 3.5mm TRRS sleeve (GND)
Please share your results with this build.