Back up and restore critical network calibration data.
Once drivers are installed, launch the Z3x Shell and activate your hardware: Z3x Samsung Tool V19.1 Setup
Run the installer and follow the on-screen prompts to complete the installation. Running the Tool Back up and restore critical network calibration data
However, for a casual user unlocking one phone, the $20–30 credit-based online services may be cheaper. But for frequent repairs, V19.1 pays for itself after a few jobs. Z3x Samsung Tool V19.1 Setup