I would consider the size of the coop itself before shutting them in.
Go out at sunset or as soon after as you can, and put each one in the coop and shut them in until morning.
Do this for as long as it takes for them to start going in on their own.
Chickens naturally want to roost high in trees.
We humans put them in coops to keep them safe from predators but a coop around sunset is a dark scary place...very cave-like.
They don’t want to go in but will soon realize it’s safe.
I’ve found my birds are more likely to go in sooner if I have windows and doors open so there’s more light for them to see by.
A light inside the coop could help them be less afraid. You could use a flashlight. Just put it close to a wall so it shines against the wall. Think nite light. Dim not glaring! If you have a window you could put it outside (I’m thinking duct tape) or if you have yard lights keep them on