Your Agents can set their own VM Greeting under the Notification Bell, additional details here.

We also recommend instead just using a shared 'System Greeting' for your inbound campaigns.

Alternate option to set VM for a Group:

1.  To configure voicemails for entire user groups go to Settings>Users>User Groups.  

2.  Search for the user group that you would like to set up a voicemail for, and click on the Edit icon to the left of the group's name.    

3.   Scroll down to Voicemail Options.  Here you can record a voicemail greeting, view numbers associated with the group, and configure Voicemail behaviors. 

Note:  Make sure to un-check the Use System Voicemail Settings box.  To learn more about system voicemails, see our support article here.