Won’t nap

My baby will not nap 😭😭 I feel like we’ve been in bed all day trying to get him to fall asleep. I know he’s tired i don’t know why he’s fighting it. I feel like this whole day had bees wasted trying to get him to sleep. I don’t want him falling asleep for bed too early but it’s 3:30 and he hasn’t napped yet. Anyone else have a baby that won’t nap?