The HT uses a DPH LAA0701 connector:
Based on the above info, Digirig Audio Cable will look like this:
DPH pin 2 (PTT) → 3.5mm TRRS ring 2 (RIG_PTT)
DPH pin 3 (GROUND) → 3.5mm TRRS sleeve (GND)
DPH pin 4 (MIC AUDIO) → 3.5mm TRRS ring 1 (RIG_AFIN)
3.5mm TRS (?) tip (EXTSP) → 3.5mm TRRS tip (RIG_AFOUT)