Formula feeding moms- when to change nipple flow?

Na

My son is a little over one month old, and he seems to be frustrated during feedings. Sometimes it takes us an hour to get him to finish, sometimes he falls asleep during the feeding and won't take the bottle, but wakes up hungry an hour later.

It seems like he just gets tired of sucking and starts to fuss.

Would it be okay to try the level 2 nipple?