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.