There are 2 parts to setting up individual voicemails. First they need to be enabled in the user profile. For this toggle to be available an extension will need to be assigned to this user.
Recording the Greeting
Open the profile menu from the top right, and select Profile.
Scroll down to the bottom and click Record. From there you can enter an extension or phone number for the system to call. The auto attendant will walk you through the rest of the recording process once the call is connected.
Once the recording is set the personal voicemail will be active. They will show up on the dashboard like normal voicemails, but the will be marked Personal, and only visible to the extension owner.