RTFM
High Beam Headlights
Use the high beam headlight button on the left side of the steering wheel to control the headlights:
Press and quickly release to flash high beam headlights.
Press and hold to turn on high beam headlights - touchscreen displays a brief timer and you must hold for the duration of the timer to latch the high beam headlights to the on position. When headlights are on, press the button a second time to turn them off.