If you want to root your device, you can use popular rooting tools like Magisk or SuperSU. However, this is an optional step and not required to unlock the bootloader.
Check connection on PC:
Tap seven times until you see "You are now a developer!". How to unlock Bootloader in XIAOMI Mi CC9 Meitu...
: Ensure you have the Mi Unlock Tool and the necessary Xiaomi USB Drivers installed on your Windows PC. Step 1: Preparing the Mi CC9 Meitu Edition If you want to root your device, you