My little one will only fall asleep on his stomach

Dawn • Baby girl to arrive April 21

I’ve tried everything swaddles sleepers just Jammie’s the bassinet, the crib, in the bed with us yet as soon as you place him on his stomach no matter what he is wearing or where he is sleeping he fall asleep instantly. But I know back is best blah blah blah. I just don’t know what to do :/