I looked it up on the homepage and you can definitely see that even for the standard hybrid hen the roof of the coop is much too low for the hens to roost comfortably.
This might work for 3-4 bantams but not for normal sized chickens.
You could just install a drawer light and change the batteries on a regular basis. But once they are accustomed to the coop again there will be no need for nightlights.
https://www.amazon.com/drawer-lights/s?k=drawer+lights
The much bigger issue is the overcrowding as omlet coops are known to...
Let them have a nightlight on a timer. Chicks are afraid to enter a dark coop.
Never let them outside at night as predators will easily find a way to get them.
Does your coop have good ventilation? Stuffy coops will also be avoided.