Bunk heater stopped working, fuel leaking

I have a factory installed bunk HVAC on my '21 Cascadia (with batteries in the frame). It stopped working this night, didn't fire as it usually did. But worse is I found fuel dripping out of the heater's exhaust tube. I understand it can be anything - the spark plug, the injector. Maybe someone has had this or similar issue? My shop told me they could only replace the injector which isn't the best option money-wise. I could shut off the line but didn't found how. As it looks like it's dripping even with the system off.

P.s Also couldn't find the diagram of the system.

 

Do you have an ESPAR under your bank or is it one that installed under the cab? I know that espars are in the compartment and easy to access, mine is under the cab as I got it. I cleaned the filter recently but didn't see much of the system from inside the cab.
P.s Thank you for your input, that really eased my mind.