Lots of trailers/5th wheels have 'scare' lights......large round lights on both sides of rig.
Mine has a porch light above entry door and another on roadside above utility area.
Also has a light under over hang to light up that area.
Biggest problem to install additional outside lighting is pulling wiring to the area.
Lots of battery operated outside use lights in aftermarket.
OR you could jumper trailer pigtail (jumper wire between positions at 11:00 o'clock & 1:00 o'clock) to have trailer running lights on for some lighting.