It's rare for chicks to figure out that they need to go back into the coop at night, so I teach mine.
It's much easier than most people think. If your coop is the big kind where you can get inside, the easiest way is to wait until the chicks are gathered together and making their trilling bedtime noises and you then get inside and coax them in with treats.
It helps to have a light inside, even a small flashlight, so the inside of the coop is lighter than outside. I call them and show them I have meal worms and they are inside in a flash. No need to run them down and catch them which stresses everyone, you included. In just a couple nights of this, they will be going inside on their own.
I suggest you teach them to come when you call them before you attempt this. This only takes a few minutes and the chicks learn fast to respond to any verbal cue if you use their favorite treat. It will make teaching them to go into the coop a breeze.