I had the same problem with my new Sunset Trail.
You have to remove the plastic cover and metal mounting bracket on one of the lights adjacent to the backup camera mounting location. Two screws held mine on. I gently pulled the light wiring through the hole behind the light mounting bracket until I found a wire nut where wires were spliced together. I took a metal coat hanger and fished it through the light hole over to the backup camera mounting bracket hole. Securely tape the pigtale to the coat hanger and pull the coat hanger back through the light hole. You'll now have the pigtail wire ends where you can splice them (wire nut) to the light wires. Took me an hour, and multiple tries. If I had been able to take my trailer back to the dealer I would have and let them do ut under warranty.