How can I do this in Phaser 3

I tried today to transfer this Phaser 2 sketch in a Phaser 3 sketch without success

var game = new Phaser.Game(800, 600, Phaser.AUTO, 'phaser-example', { preload: preload, create: create, update: update });
var leftEmitter;
var rightEmitter;
function preload() {
    game.load.image('sky', 'assets/skies/cavern2.png');
    game.load.spritesheet('balls', 'assets/sprites/balls.png', 17, 17);

}

function create() {

    game.add.image(0, 0, 'sky');

    game.physics.startSystem(Phaser.Physics.ARCADE);

    leftEmitter = game.add.emitter(50, game.world.centerY - 200);
    leftEmitter.bounce.setTo(0.5, 0.5);
    leftEmitter.setXSpeed(100, 200);
    leftEmitter.setYSpeed(-50, 50);
    leftEmitter.makeParticles('balls', 0, 250, true, true);

    rightEmitter = game.add.emitter(game.world.width - 50, game.world.centerY - 200);
    rightEmitter.bounce.setTo(0.5, 0.5);
    rightEmitter.setXSpeed(-100, -200);
    rightEmitter.setYSpeed(-50, 50);
    rightEmitter.makeParticles('balls', 1, 250, true, true);

    // explode, lifespan, frequency, quantity
    leftEmitter.start(false, 5000, 20);
    rightEmitter.start(false, 5000, 20);
}
function update() {
    game.physics.arcade.collide(leftEmitter, rightEmitter, change, null, this);
}
function change(a, b) {
    a.frame = 3;
    b.frame = 3;
}

the collision was the Problem

Hi,
From the docs:

A Particle is a simple Game Object controlled by a Particle Emitter and Manager, and rendered by the Manager. It uses its own lightweight physics system, and can interact only with its Emitter’s bounds and zones.

https://photonstorm.github.io/phaser3-docs/Phaser.GameObjects.Particles.Particle.html

Thx Blun
I figured out that emitter collisions with Phaser 3 is not possible, so it’s an back step to Phaser 2