How can I enable automatic start-stop function in my Audi A6?

I recently purchased an Audi A6 but the automatic start-stop function doesn't seem to be working. How can I activate it and is there any way to disable it?

To enable the automatic start-stop function in your Audi A6, simply press the button located on the center console. If the button is illuminated, the function is active. You can also check your vehicle's manual for specific instructions on how to enable or disable this feature.