Download software 

Launch ZTE Qualcomm Writer software

 Click "Refresh" button to detect modem

 To access support area website click "Enter Support Area" button

In opened page's search field type: "64K_BD_IDEAMF190V1.0.0B0_Decustomize.dgtk" and hit "Enter" button on keyboard

 Select the offered file and click "Download" button

On ZTE Writer software press white paper icon on right side of the line under "Firmware Digiteka File", then navigate to downloaded file, select it and click "Open"

 Now press "Update" button on ZTE Writer software

 Wait for update to be finished

 After update completes, device redetects itself on the program

 Modem is now unlocked and usable with any sim card.