The web interface should automatically prompt you to enter the 16-digit unlock code. Configure APN:

(often called "Huawei Multicast Upgrade Tool"). Standard Drivers for Huawei mobile devices. Enter Download/Flash Mode

This is the safest method as it does not involve modifying the router's core system files.

Do not attempt a firmware update on a locked router. It can brick the device. Use one of these three methods first.

: Power off the router and insert a SIM card from a different network provider.

Array
(
    [LANGUAGE] => en
    [GEO_IP] => 185.104.194.44
    [GEO_COUNTRY] => PL
)