^hot^ Free Link: Zte Zxv10 B866v2 Unlock
This method doesn't actually unlock the firmware but bypasses the ISP lock screen by exploiting the Google Assistant. You temporarily block the box's internet access to bypass the login, use voice commands to open the Play Store, and install a custom launcher or "Button Mapper" to override the home button.
If you are looking to bypass the main launcher without a full flash: Access Recovery Mode : Use a keyboard to navigate the boot menu. Reboot System zte zxv10 b866v2 unlock free link
If the official ZTE unlock page doesn't work for you, there are alternative free link methods available: This method doesn't actually unlock the firmware but