It may seem a silly question but have you verified the outlets function on shore power, your unit has a GFCI on one of the outlets that will kill power to all of them.
According to your manual if the Genny was a factory install there is a control unit tied to the main power panel that is supposed to automatically power the unit from the Genny if shore power is not available.
If your unit was generator ready but none was installed at the factory you have to plug your shore cord directly into the Genny as another person stated earlier.