Can't record an outgoing greeting

I think I'm going insane. Every single post tells me that to set my voicemail message I have to hit "Greeting" when I go to my voice mail box. It's not there. I hit the green phone icon and that takes me to the Voicemail page. There is nothing on top that says "Greeting." Nothing on the bottom says "Greeting". Those are Favorites, Recents, Contacts, Keypad, and Voicemail. I've pressed the Voicemail icon at the bottom right but the mail is empty so that goes no where. In the middle of the screen is the box that says "Call Voicemail". Help. It's a 6(s).