Your baby is a newbie, and practice makes perfect
Congratulations on your baby and welcome to motherhood (maybe again if this is baby no. 2, 3, 4, etc.)! Newborn naps are sporadic. All. Over. The. Place. There's not much consistency or predictability.
Your baby is likely between 0-16 weeks, and if they're not, I'm sorry to say, but their naps sure are acting like it! The good news is, practice makes perfect, and we can fix things with a bit of time and consistency.
At this stage, it's easiest to practice the first few naps of the day in the crib since the sleep pressure is higher in the morning.
By mid-late afternoon and into the evening though, naps can be more of a battle. Offering naps early and often during the newborn stage can help with preventing overtiredness, a very common cause of poor sleep at this age.
That, along with a bit more maturity, and your baby's naps should start to consolidate more and more as they get closer to 6-months of age.
Set the stage for sleep - if you aren't already, make sure you have a nap time and bedtime routine. Make sure it's totally dark, you're utilizing white noise around 60 dB, swaddling if your baby is between 0-8 weeks (no more swaddle by 12 weeks…use a sleep sack now!), and even practice laying your baby down awake to see what happens. Help them if they need it. Pacifiers can be useful at this age too.
Remember, time, consistency, and practice are your best friends right now!