Do i have to pay equipment fee with gigabit fiber if i own an NVG 599?

So i have a question, If i own an NVG 599 (long story short, my friend lost one when he moved, paid the fee when they cancelled the service and found it in a box in their attic later and gave it to me), would i be able to use it and would i still have to pay the "lease equipment" fee for AT&T Fiber service if i were to use it? I know they probably cancelled the NVG 599 when my friend paid for the lost modem(NVG 599), but they can always just reactivate it.