Nap time help!

Anyone have any luck recently transitioning their littles to nap in the crib instead of being held? We had to wait until our sons reflux got more under control, but now I’m ready for him to start crib napping. We did Ferber at night a while back and he goes to sleep totally fine on his own but naps are a different story. I don’t know what to do, and I definitely don’t want him to start associating his room with something negative and ruin the night sleep. Help!!