Click the button. The tool will communicate via ADB, request Root access on the phone, and write the data. Patching Certificate :

The release of Binary 8 firmware introduced significant security hardening, rendering older repair methods (such as standard EFS resets or older Sboot files) ineffective. The Z3X Box (Samsung Tool Pro) provides a diagnostic interface capable of repairing the IMEI, provided the device’s bootloader security is temporarily bypassed.