Unlocking the bootloader of a (STK-L21/STK-LX3) is the essential first step for advanced customization, such as rooting or installing custom ROMs. However, Huawei officially terminated its bootloader unlock code application service on July 25, 2018. Since the Y9 Prime 2019 was released after this date, official codes are generally unavailable directly from the manufacturer. Bootloader Unlock code Huawei Y9 2019 - HUAWEI Community
I understand you're looking for a to unlock the bootloader on a Huawei Y9 Prime 2019 (model code typically JKM-LX1 , JKM-LX2 , JKM-LX3 ).
: On his PC, PotatoNV flickered to life. He selected the bootloader type and hit "Unlock." The Moment of Truth
Potato NV (paid) sometimes works without opening the phone.