Need help with voicemail

So I’m somewhat new to FreePBX and I have seemed to hit a wall.
I’ve got a voice mail set up for a ring group I’ve created, but I am unable to figure out how to get either the voice mail box to show up on multiple extensions, or at least the MWI to show up on all the extensions.

Edit: As a note each one of these indivual extensions has q unique VM that I want to keep

Unless I miss-understand your request… you are looking to have more than one VM assigned to an extension?

The primary VM for the extension, plus another VM shared by multiple extensions.

I believe this article may assist you: