Huawei has released two types of E8372 model, one is E8372s which can be unlocked by unlock code only, but the device with h suffix (E8372h) needs to be flashed before unlocking. A few days back, we had written about unlocking of E8372h-608 (Altel Kazakhstan). In this post, we have compiled all firmware and WebUI / dashboard of E8372h device.
If any firmware is missing let me know via comments, it will be updated soon. You can also refer unlocking of MTS 8211F modem of Russia.