Im on an iphone XR and when I switched over to Visible ( which works awesome ) I found that the Call Forward option under Settings/Phone was no longer there! Call forwarding IS a feature offered by Visible but I could not find anything explaining how to use it.
To use Call Forwarding look at this Verison page: Turn Call Forwarding On from Device | Verizon
To turn OFF call forwarding look at this page: Turn Call Forwarding Off from Device | Verizon
Hope this helps someone.