Firmware is the foundational software embedded directly into your smartphone's hardware. For the ZTE Blade V40 Smart, the official stock firmware is based on Android (wrapped in ZTE’s proprietary MyOS interface).

Only resort to manual flashing if:

Unisoc/SPD Android USB drivers to ensure the PC recognizes the phone in "Download Mode." Firmware File: Usually a large file with a .pac extension. Flashing Process (Summary)