Go to https://settings.webex.com and select Webex Calling.
From the Calling User Portal, go to Call Settings, toggle on Remote Office.
Input a valid number for the new calling location.
Calling User Portal | Set up Your Remote Office Device
With Remote Office, you can use your home phone or mobile device as your business phone when you can't be at the office. This directs all incoming calls to ring your remote office device. When Remote Office is enabled, your remote device rings, and the call is connected as you were placing the call directly from your office phone.