Ensure your drivers (ADB and Fastboot) are installed on a PC.
fastboot devices
This process voids your warranty and makes your device more vulnerable to malware. Hardware Risk: How to Unlock Bootloader in HUAWEI P30 Lite phone
Before you begin, you must understand the risks and requirements specific to Huawei devices: Ensure your drivers (ADB and Fastboot) are installed on a PC
Your bootloader is unlocked. Now you can: How to Unlock Bootloader in HUAWEI P30 Lite phone