If the refer is a typical RV propane type then use propane while driving. Most will use AC when plugged in and automatically switch to propane.
If it's a AC only type (res refer) then your AC power comes from:
1. Shore power
2. Generator
3. Inverter which converts 12V battery power to 120V AC power.
Recommend you call the demo guy for clarification. Better ask for instructions via email.
Based on your post using the refer may not go well until you get the process down pat. ABOVE ALL food spoils above 42 degrees so get a thermometer. :(
