How to set up voicemail if I don’t see the Set Up Now button

How do I set up a voicemail?? I found a lot of articles about how to do it but when I try to set one up, I don’t see the Set Up Now button. I’ve never set up a voicemail before and I don’t know why I can’t do it I included screenshots of what I get when I try to set one up.

When I try to call my voicemail, I get this error but it then goes to calling it. How do I fix this? I need a voicemail!

Thank you for trying to help!