To configure a mailbox for your voicemail for your account, you will first need to create one before adding it to your call route!
In order to do this, go onto My Dashboard > My VoIP > Config > Mailbox.
Here, clicking Create mailbox will allow you to nickname your mailbox, change the greeting (which can be personalised) as well as change the extension number and give the mailbox a password. The extension number is the number you will ring from your device in order to access your mailbox. You can also enter an e-mail address so that you will be notified every time a voicemail has been left in your mailbox. After adjusting those settings to your liking, click the tick and then your mailbox will all be set up.
The next step will then to be to add your newly created mailbox to your call route! In order to do this, head to your call route and under routing modules, click the ‘send to voicemail’ option and select your newly created mailbox from the drop down menu. After doing that, click the tick on the right hand side, assign it to your number and you’ll be good to go!