Age is needed but so is enough light daily as well as proper nutrition for them to be laying. If you want to force laying then I suggest putting a light in the coop that comes on at 3AM and goes off at 9AM. That way they get all the light needed to stimulate egg production and they will go to roost normally. After 6 weeks of this they will probably start laying. Good Luck Happy Holidays!
I have them in an outside run and on proper nutrition , same as all my other birds that r laying, I talked to the breeder that I got them from and she said some of hers don't lay till eleven months so I'm guessing thats that is it