When making your reservation at the RV park, or upon arrival, let them know that you need a 30 amp site. Turn off the truck and turn off the APU. Never run your APU at a campsite or campground. Not only is it against the rules, but you could be jeopardizing other Davnic drivers from staying at that park. Also, very important to make sure your water valve is closed off so that water from your sink or shower is not running out in the campground. Once you leave the property, then open the valve and allow the water to drain.
Each truck should be equipped with a yellow 30 amp plugin as pictured here.

Under the bunk on the passenger side is where this plugs in. Notice the notch. It only plugs in one way. Once plugged in, screw tight the black collar.

Next you will need a 30 amp cord. Davnic does not provide these and you will need to purchase one yourself. (Available at most Walmart's in the RV section) Run your 30 amp cord to the RV site plug in. If the site has both 30 and 50 amp plugins, make sure you are using the 30 amp. Finally, Flip the breaker to the on position. You should be hooked up to shore power now. Check you power inverter reading in the bunk. It should say shore power. You can now run your rooftop AC and any appliances without the use of your APU. Enjoy your quite nights.
If you are staying at a friend or family members home and you want want to run off of shore power, you will need a 30 amp to 120 watt adaptor that goes on the end of your 30 amp cord. You can then plug into an extension cord. We found ours at Home Depo. We have also seen them at some Walmart's, and Lowe's The image below shows what the adaptor may look like.

So I am now reimbursing you for the 30' 30amp RV cords, Just send the receipts in and you'll be reimbursed. The cord will stay with the truck if you are reimbursed.