What is a bootloader you might ask?
Start off by connecting your phone to your computer via a USB-A to USB-C cable, you should already have one since one came in the box.
Next, head into Developer Settings and enable USB Debugging and OEM Unlocking.
With your phone connected to your computer open up ADB and issue the following:
You should see a string right beneath it which tells you that your phone is connected and ADB has detected it.
Now issue the following to reboot your phone into the bootloader:
Once your device boots into the bootloader you’ll need Fastboot. Don’t worry, if you followed the guide above on setting up ADB, you should already have it by now.
Issue the following to unlock the bootloader:
You’ll now be prompted with a message asking you to confirm the action, proceed by selecting YES
Issue the following to reboot your phone
Congratulations, you just unlocked your phones bootloader.