Just to clear up a few points.
You say you're driving via the generator. Do you mean Regeneration from the EV motors?
The generator is run by the petrol engine (ICE)
Do the SAVE and CHRG messages come up on the dash when you hit those buttons?
Is the fuel gauge indicating the presence of fuel?
After that it's the usual ICE fault finding - fuel pump working, spark at the spark plug etc, which will be tricky as you can't crank the ICE.