The bootloader on Nokia 7.2 and Nokia 6.2 was unlockable until the November 2019 Security Patch release. In December, Nokia released a major update which fixed a number of bugs. The update also disabled the bootloader unlock ability. Now, if you want to unlock the bootloader on Nokia 6.2 and 7.2, the only way currently is to downgrade the phone to the old software.
It is not possible on the user’s end to do the downgrade. So, your only option is to get it done at Nokia Care. Alternatively, you can buy our unlock service and we will do the downgrade remotely over TeamViewer.
Once downgraded, you will be able to unlock the bootloader as explained in several other guides.