Zello gateway radio

I was hoping to see if it possible to use the digirig to create a RF to Zello gateway for my department. I have a baofeng APRS cable and one of the departments old Kenwood HT (which had a speaker/mic port) plugged in to the digirig. The sound from the radio is a little hot but I can back it down. However, the digirig does not activate the PTT and I can not use VOX on this radio. I have the Rev 1.9 digirig. Is it the cable, radio, or the digirig?

What are the PTT methods available in the software configuration?
Digirig supports PTT by RTS in all radios and via CAT command in capable radios.