SigmaKey will instruct you to allow Root access temporarily (if phone is not rooted, it will attempt a temporary root exploit). For the VFD 630, SigmaKey leverages a known CVE vulnerability in the MT6739 boot chain.
There are two ways SigmaKey handles this device, and both work well: vodafone vfd 630 unlock sigmakey
The lock information, often referred to as a Network Control Key (NCK), is stored in the device's memory. Unlocking the phone essentially involves either entering a correct, unique NCK code or rewriting the phone's security area to remove the restriction entirely. SigmaKey will instruct you to allow Root access
While holding the keys, plug the micro-USB cable from the PC into the phone. vodafone vfd 630 unlock sigmakey