If Huawei phone ask for a ?Simlock Block Unlock Reset Key? after you insert another Network SIM Card,
this mean your phone is blocked because of too much wrong code.
In this case you need to use the tool "Huawei (Simlock Block Unlock Reset Key)"
CID READER FROM DOWNLOAD SECTION
Read your phone IMEI and CID
Start with the phone disconnected from the USB cable.
Dial *#3646633# or #*888# on the keypad to enter Engineering mode.
Go to Set UART > UART Setting.
Set PS Config section to USB Port, 115200.
Press OK and wait until the phone is powered off.
Power on the phone and wait until it fully starts up.
Download the Huawei IMEI/CID Reader Utility
Connect the USB cable to the phone and complete the driver installation.
Once the driver is installed, click Read to read the IMEI and CID from the phone.
HOW TO ENTER NP CODES IN HUAWEI
Insert an unsupported SIM card and power on the phone.
Once you see the message Enter Input NP code
Enter the unlock code you have received from us
Your Huawei is now unlocked