If you have a 50 amp electrical service, the optional generator from Heartland would likely be an Onan 5500 generator. If 30 amp, it might be an Onan 4000. To find out for sure, you could call Heartland Customer Service at 877-262-8032 / 574-262-8030. Have your VIN # ready.
If the generator fuel station and pump are already installed, to install the generator, you'd principally be dealing with a bit of wiring and installation of exhaust pipe.
Another way to go would be to get a standalone generator (inverter type) that the shore power cord can be plugged into.