If you are dealing with a locked iPhone or iPad, you’ve likely come across the tool. It is one of the most popular free solutions for bypassing Activation Lock on Checkm8-compatible devices. However, the most common hurdle users face is the "ECID not registered" error.
Open the FRPFile bypass tool on your PC and connect your device in Recovery or Normal mode. The tool will automatically display your ECID in one of the info boxes. Click on it to copy it.
Navigate to the official FRPFile website (frpfile.com). Look for the "Registration" or "ECID Register" section.