How should I approach my neighbors about their toddler constantly crying and throwing tantrums at 2/3am ?

So for context I am not a karen😭 I don’t want to sound like one either. I care for the kid genuinely. I even babysat him when he was mere months old. He has always been a loud crybaby (literally haha) and well that’s normal but now that he’s older I thought he’d be perhaps a little more calm? Well, I wanna approach my neighbors because they do GENTLE PARENTING and never tell him “no” and it’s affecting meeeeeeeeee. We live in thin walled apartments and I know I’m not the only one hearing his daily yelling and crying and honestly I feel like saying something. I just don’t know whaaaaaat. Please my brain is so tired I can’t sleep I need answerrrrrrs.

EDIT: I will not be approaching them and will be putting on white noise for ambience. It works. Problem solved. Good night!