There's a YouTube video out there demonstrating the installation of a wiring kit on a Kona EV, it's not at my fingertips but I'm pretty sure I saw it mentioned a while back on this forum.
After having the local U-Haul dealer install a 2" hitch, I went back to have a wiring kit installed because I wanted to add lights to my bike rack for a long road trip, thinking it would likewise be rather trivial to do. They gave up, telling me they'd have to dismantle the bumper to run the wires (which I think is incorrect) and they slightly damaged one of the taillights in the process of putting it back together. So I don't recommend having U-Haul put in the wiring package, the hitch part went OK once they figured out they needed to cut some plastic to make it work.