Firmware for the H168N is highly region-specific. Using the wrong file your device.
This update resolves several high-severity vulnerabilities discovered between 2018 and 2021: Improper Access Control (CVE-2021-21730): zxhn h168n v22 firmware update download fix
Wait for the router to finish; it will likely reboot automatically. power off the device during this process to avoid bricking it. Issues Fixed by Updates Updating your ZXHN H168N V2.2 address critical security vulnerabilities and bugs: Enhance Your Wi-Fi: Easy Wireless Router Firmware Update Firmware for the H168N is highly region-specific