Napping in crib...

Our son has been napping in his bouncer since birth pretty much (after he stopped sleeping in our arms) and won’t nap in his crib. He will just scream and freak out unless we get him out -he’s 6.5 months old. He’s outgrowing the bouncer but we really want him to nap in his crib regardless. He’s done it like one time after he got excessively tired and I rocked him for a long time. And he slept 38 min. He used to nap at daycare in his crib in the daytime, in a bright noisy room but they gave him a pacifier. He’s never used one at home. And his grandparents watch him twice a week since we work from home and it’s hard to manage that and watching him, and when he’s there they hold him for naps. For me, he won’t rock to sleep for a nap during the day and I don’t have time for that when I’m working from home! Any advice? I know we waited a looooong time but it’s been so convenient for us to bounce and watch him while he sleeps.