3 month old won’t nap

My son just turned 3 month old, he absolutely refuses to nap unless he’s being held. Which makes it incredibly difficult to get anything done. As much as I love to hold and snuggle him, holding him the entire time he naps it’s just not practical. He sleeps fantastic through the night alone in his bassinet, but when it comes to napping I can’t put him down. The first month and a half he slept great on his own for naps, and now it’s becoming Increasingly difficult to put him down. Any tips to get him to nap on his own?