2x above ... You can mix & use a gallon sprayer, if it was used prior for something else make sure it's rinsed out well. If you don't free range your birds but have a run, keep them out of the coop & use protective clothing/mask and mist spray every corner/crack, nest boxes, roosts & bedding, repeating in 7 - 10 days as eggs hatch. You can mist under the chickens wings & vent area; said to be the spots mites/lice like to gather; I'd do their back too but lift feathers.
I prefer using Garden & Poultry Dust (permethrin main ingredient) monthly under their wings, vent area and sprinkle their back area working it in. Plus I dust their CH shavings monthly with DE ... Many say they use DE for mites, I've read it doesn't kill but I use it around their enclosure and shavings as a preventative cause it's cheaper and I can use in the garden & yard; lots of wild birds.
I've read that you could also mist spray at night when they're roosting, again protective clothing/mask, spray as mentioned above and under the chickens as they roost. I never did this, I have a neighbor kid that dunked his fighting roo, it ended up not surviving.