We put ours in their run permanently around 8 weeks (their coop is attached to their run and I had to throw them in one time and out one time, but after that they were happily using it themselves).
If I might make a suggestion; I have bought both my runs, a chicken feeder, other chicken related...
My own experience is; I bought fake eggs, put them in the nesting boxes - nope, not interested. Nesting boxes period - one used it once; then one of the girls laid an egg in the safety of the roost (which is raised by using cinder blocks on either side). Now everybody loves that area and all the...
The tell with mine that they were ready, was that they squatted all the way to the floor when I petted them and they put their wings out somewhat - being very docile. Before that, most of them wouldn't let me pet their backs and were skittish.
We live in NW GA and like being in charge of our own lives.
Bought 6 (they, and my husband, told me at least 2 wouldn't survive) Rhode Island Red chick layers from TSC and brought them home - surprise, they all survived; I have a grow room (partially) 3' down below ground surface, complete with...