Add more ventilation? That looks like plenty in my eyes
You can’t see the whole coop in the photo that the OP posted, so watch the video to get a better idea of what it looks like
They’re only five weeks old, they need to get into a routine. Usually they copy what the mother does but you will have to teach them, put them on a roost every night and they’ll get used to it within 2 weeks. That’s my advice
Why add a light in the coop if they only use it at night, chickens prefer to sleep in the dark. It’s the beginning of summer not the middle of winter. Try teaching them to sleep on the perch at night, they’ll eventually get the swing of things
Is that thing on the side not a window ?
Chickens have no problem sleeping in the dark. What do they do in the wild ? Make a fire and sleep by it ?
The chickens only use the coop at night or when their laying an egg, at night it’s supposed to be dark, maybe putting a light on the outside so...