How do I activate multitouch?

Phaser 3
1

I want the cars to move at the same time when their respective buttons are touched at the same time.

A snippet of my code

buttonRed.on('pointerup', () => {
    carRed.Y += 50
})

buttonBlue.on('pointerup', () => {
    carBlue.Y += 50
})
2

have you added any more pointers in the game? ( [scene].input.addPointer([number]) )

3

http://phaser.io/examples/v3/category/input/multitouch

4 
create () {

    this.input.addPointer(3)

    buttonRed.on('pointerup', () => {
        carRed.Y += 50
    })

    buttonBlue.on('pointerup', () => {
        carBlue.Y += 50
    })

}