On the phone enable Developer options. More info here.
Find the “OEM unlocking” button and enable.
![](https://www.incredigeek.com/home/wp-content/uploads/2020/03/Allow-OEM-unlocking-637x1024.png)
Reboot phone to bootloader.
Plug phone into computer and computer run
sudo fastboot flashing unlock
Use the buttons on the phone to select and enable unlocking.