“amab genitalia” doesn’t mean anything. There are intersex amabs with genitalia different from most perisex cis men’s. there are transfeminine amabs who’ve gotten surgery which makes their genitalia different from most cis men’s. if you mean “having a dick”, or perisex cis male genitalia, then say that
Edit: and even “perisex cis male” doesn’t narrow it down! It’s rare, but they can also have genitalia that doesn’t conform to your expectations. Penis, scrotum, vagina, vulva and etc. are not bad words!