You only have 10 attempts to enter an unlock code. If you exhaust these, you will need a "Counter Reset" tool or a deep firmware flash.
If you want to switch to a more affordable data plan or use a local SIM while traveling, you’ll need to deal with the . Here is everything you need to know about liberating your hardware. Why Unlock Your Huawei E173u-1? Huawei E173u-1 Unlock Firmware
Plugged directly into a USB port (avoid USB hubs). You only have 10 attempts to enter an unlock code