Use a LAN cable; never try to flash firmware over Wi-Fi.
While specific steps vary by firmware version, the general workflow is as follows: b311221 unlock firmware link
This article provides a comprehensive breakdown of what the B311221 unlock firmware is, where to find genuine links, how to safely apply the update, and what to do if things go wrong. Use a LAN cable; never try to flash firmware over Wi-Fi
Click “Upgrade” and wait. Do not power off, unplug Ethernet, or close the browser. The router may reboot once or twice. This process takes 3–5 minutes. Use a LAN cable