For the MAR-LX3A (typically the Latin American/Canadian variant), ensure you are downloading a version higher than or equal to your current build.
How to Download Huawei P30 Lite MAR-LX3A Firmware huawei p30 lite marlx3a firmware download upd
Q: Can I use MAR-LX3 firmware on my MAR-LX3A? A: No. The partition table differs. Use only MAR-LX3A. huawei p30 lite marlx3a firmware download upd
Connect to a stable Wi-Fi network and ensure your battery is at least 30% charged. Go to Settings > System & updates. Tap Software update. huawei p30 lite marlx3a firmware download upd