You can forward your calls through the mobile app.
Mobile Call Forwarding Steps:
1. Log into the user app
2. Select Call Forwarding from the menu
3. Forward To – This is a 4 digit extension or a 10 digit number prepended with the dial out digit. Ex 819998881234
4. Voicemail – If you slide this – it will forward all your calls immediately to Voicemail
5. Enter the number in the Forward To box or Voicemail
6. Click Save when complete