The best way to switch on the Tivoli's headlights is to leave it as this setting as shown in the picture. This lever can be found on the left side of the steering wheel.
The switch on the left should always be left on AUTO as shown below. This means that your headlights would be on whenever you are in a dark place or if it's at night. It will turn off automatically once you enter a bright area.
To activate the high-beam, just pull the same lever here towards you for a quick flash and push it away from you for the high-bean to remain on.