Unsure of what it is, but it appears to have a dummy plug protecting the terminals on the end of it. I would just zip tie it to something tucked away above the liner.
Looks to be a deadhead cord inserted into c3412 which would take inverter 120v power to the bed which by the looks of it you don't have (at least for the 2kW inverter)? Orange tape and orange wires are typically for HV. Very strange it didn't just use a cap a c3412.