Voicemail access on new iPhone 13
I have a new iPhone 13 and when I go to voicemail instead of displaying the recent messages I just get a blank screen with the message asking me to set up a password and a greeting. When I press the "set up" button it takes me to a screen with a numeric keypad and asks me to enter a voicemail password. I have no memory of even having a password for my voicemail, so I assume they mean enter a new one. So I enter a series of numbers, and after asking me to confirm those numbers, it then gives me the message "Voicemail Unavailable - could not authorize access". I really don't know what to do next - anybody have any ideas? Thanks in advance!
BTW, I have been using iPhones for 10 years and I have never encountered this situation - I always was able to access my voicemail by just pressing the sub-menu at the bottom of my screen, without having to enter a password.
iPhone 13 Pro, iOS 15