Here is a summary of the changes in the EMUI 12 update for Huawei Y9 Prime 2019 (STK-LX3):
: Always create a full backup of important files before updating to prevent potential data loss during the installation. Sufficient Power & Storage firmware huawei y9 prime 2019 stk-lx3 emui 12
For STK-LX3, Project Treble GSIs (A/B partition) work well. Flash via TWRP or fastboot. Here is a summary of the changes in