great first race day !!

the button is under clutch pedal, has to be there, to be legal. rule book states, two steps must be activated by brake pedal or clutch pedal , no buttons on shifter or steering wheel.
reason , is to prevent adjustable buttons use. also, it releases just before clutch pedal engages, the motor is starting to rev up as clutch engages, this prevents a bog condition. that's how he has it setup.