The verb is 재확인하다, which can also mean 'reconfirm' (as in, to reconfirm a reservation). If you want to translate it more literally, you could say 다시 확인하다 ('check again'), but 재확인하다 is more common.

I just give you some conversation examples: - When you're asking it, you can say "다시 확인해주세요" or "다시 확인 부탁드릴게요" (more polite). - When you're being asked it, you can say "다시 확인해볼게요" (polite) Have a good day!