Leave the phone plugged in.
Turn on the iPhone and use the provided PIN to unlock
Tap the Phone Icon
Foward ALL Calls
Call *72 + the 10-digit number that you want to forward your calls to without the 1- for example, *72-908-123-4567
Suggest you call the MOD phone and test that the designated MOD number rings, the MOD phone should not ring.
All calls are now forwarded
Forward ONLY Unanswered Calls
Call *71+ the 10-digit number that you want to forward your calls to without the 1- for example, *72-908-123-4567
Suggest you call the MOD phone and verify the phone rings and then transfers to the intended number when unanswered.
Unanswered calls will now be forwarded.
Turn Off Call Forwarding
Call *73. You should hear a confirmation tone or message. It may sound like a busy signal, but that's OK. It still means your Call Forwarding has been turned off.
https://www.verizon.com/articles/call-forwarding-everything-you-need-to-know/