Question about De'Longhi Magnifica S

The ECO button is not a distinct physical button on the Magnifica S (ECAM 21.117.SB) model; ECO mode is activated or deactivated by holding down the steam nozzle button (top right) when the machine is off, then using the Espresso button to select the state and the Long Coffee button to confirm. The ECO light will then be solid (activated) or flashing (deactivated) during this operation.