Unless you need specific app compatibility (some banking apps no longer support Android 6), stay on the latest 7.1.1 build.

For users who prefer a fully automated tool, the (Line Brush) PC client can handle everything:

Legitimate sources (avoid unofficial downloads to prevent malware):

The ZTE 9030 firmware can be updated using the following methods:

Unlike major brands like Samsung or Google, ZTE firmware files are not always hosted on a central public server. Here are the best places to look:

A green checkmark or "Finish" notification will appear once the process is successful. Official Resources