Release the buttons once the Huawei logo displays on the screen. The device will automatically enter software update mode and begin reading the dload folder.
Firmware is region-specific (e.g., C431 for Europe, C185 for Middle East). You must match the region code exactly to avoid soft-bricking. Huawei Central Official Download & Update Methods Over-the-Air (OTA) Update: Navigate to Settings > System & updates > Software update huawei p30 lite mar-lx1a firmware download
The (is it boot looping, soft-bricked, or running fine?) The current EMUI software version you are trying to change Release the buttons once the Huawei logo displays