Install openwrt on xiaomi mi wifi


I have a mi wifi mini access point with an old custom firmware. I am trying to upddate it using this firmware bu tI am getting an error:
Firmware update: Incorrect image ProductID: OpenWr! Expected is MI-MINI.

How can I install the new firmware?

This is the current mtd;

/opt/home/admin # cat /proc/mtd
dev: size erasesize name
mtd0: 00030000 00010000 "Bootloader"
mtd1: 00010000 00010000 "Config"
mtd2: 00010000 00010000 "Factory"
mtd3: 0011f1e0 00010000 "Kernel"
mtd4: 00e50e20 00010000 "RootFS"
mtd5: 00040000 00010000 "Storage"
mtd6: 00f70000 00010000 "Firmware_Stub"