For ISP-branded devices, the only legitimate source for a firmware download link is the ISP’s own support portal.
Many users Google "ZTE router firmware upgrade download link" and click the first result. Stop. Dangerous places include: zte router firmware upgrade download link
Many ZTE routers have a built-in auto-update feature that provides a direct download link. For ISP-branded devices, the only legitimate source for
Obtaining ZTE router firmware is not a straightforward process like downloading drivers for a graphics card. ZTE operates on a Business-to-Business (B2B) model, supplying hardware to Internet Service Providers (ISPs) rather than selling directly to consumers in many markets. Many ZTE routers have a built-in auto-update feature
Consequently, there is no single public repository for ZTE firmware. Firmware is highly specific to the hardware revision, region, and ISP customization. Installing the wrong firmware will permanently "brick" the device.