have you followed this instruction?
UNLOCK INSTRUCTIONS:
Phone must be rooted!
If the software can't root the phone automatically,
then you must root your device manually.
1. Power on the phone.
2. Tap 7 times on 'Build number' in 'Settings'-'About phone' to enable 'Developer options',
go to 'Settings'-'Developer options' and enable 'USB debugging'.
3. Connect the phone to PC with USB cable, install drivers if needed.
4. Select device in ADB settings.
5. Press 'Unlock TMB via Server' button for direct unlock, write your login and password in window if it will appear.
(Login and password will be saved as default after first input and can be changed in settings)