If you're talking about visual voicemail, that';s how some carriers do it. With others, it's something you can set. But calling the carrier will clear it up for you. (Call 611 on the Note 8 and, if you have to do things with the phone, like make a call to your voicemail, ask the customer service associate for a direct number at which to call him/her back [or they might call you back) using a different phone].)
Voice mail is run by the carrier, not by the phone, and they all do it differently, so they're the ones to tell you ho0w to do things with/to it.