Unlike a serial number, which is unique to your specific physical machine, a Dolce Gusto "code" usually refers to two different things:
Most "generators" require the user to complete a series of endless surveys, download suspicious software, or click through intrusive ads to "unlock" the generated code. The site creator makes money from your clicks, while you receive a fake or non-working code.
If you bought a second-hand machine and the card is missing, check the machine itself.
