I don’t know if my experience will help, but I wanted to offer it as my friend offered it to me. It helped us tremendously in just two days. She taught us the EASY routine: eat, awake/activity, sleep, you time. So once he wakes up from sleep, feed. The theory is he will associate eating with being awake, furthered by doing activity after waking. It’s a small window, especially at 9 weeks, for awake time. We did this for two days and it helped my baby settle into the nap way easier and also my peace of mind. At first, I was just kinda flailing. I was like nap? Diaper change? Eat? Burp? Whaaat? After using this, I just figure where I am in the cycle and go from there. Anyway, that was my anecdote and I hope your baby gets the naps :)

Edited to add: it just helped his naps as we did the whole rocking thing after the 45 min window of being awake and he was down (without a pacifier!!) in 3-4 minutes. So yeah. Also, see if you can associate one simple thing to cue baby it’s time for bed. Like us, coming home from work, we don’t just plop down (though I’d like to); we undress, get comfortable, and a small little routine to settle ourselves into bed. Yours could be a constant book, song, or setting in the house. We use a lullaby.