T4V0 , 6 months ago

You need to unlock your bootloader.

1. Enable USB debugging in the developer options;
2. Reboot the phone in fastboot;
3. Connect the phone to your PC;
4. Run the commands bellow, line by line:

<span style="color:#323232;">touch key.txt
</span><span style="color:#323232;">fastboot oem get_unlock_key key.txt
</span><span style="color:#323232;">fastboot reboot-bootloader
</span>

5. It should show a warning that the bootloader is unlocked;
6. Reboot in fastboot and install TWRP again.