https://uberant.com/article/2075954-why-should-you-get-your-keys-cut-in-liverpool-/

How will the auto locksmith make a copy of your car keys? It is a matter of leveraging the right tools for the job. If your car is on the older side and it still utilises a traditional metal key accompanied by a separated transponder chip, the process of copying it will necessitate finding your vehicle’s VIN and looking up the car’s key code database. The locksmith you call will create a duplicate of your car key either by using the original or the vehicle’s lock codes. Then, he will connect a diagnostic tool to your car’s OBD port and sync the new transponder chip inside the key fob with the vehicle’s immobiliser.