Won’t nap!

My 3 month old is so hard to get to sleep for naps and will only be asleep for about 30 minutes then wakes up. I sometimes can get him back to sleep but not always. This makes him super cranky in the evenings. He doesn’t take a soother either. Once he is cranky in the evenings he is so hard to get to sleep I have to rock him for so long 😭 tips? TIA