How to include a tile map in phaser.js?

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How to properly connect a tile map in phaser.js?
There is a code:

var game = new Phaser.Game(600, 450, Phaser.AUTO, 'game-field', { preload: preload, create: create, update: update });

function preload() {
  game.load.image('tiles', '../assets/tilea2.png');
  game.load.tilemap('tilemap', '../assets/map.json', null, Phaser.Tilemap.TILED_JSON);
}

function create() {
  game.stage.backgroundColor = '#787878';
    map = game.add.tilemap('tilemap');
    map.addTilesetImage('tilea2.png', 'tiles');
    layer = map.createLayer('world');
    layer.resizeWorld();
}

function update() {
}

Unfortunately it doesn't work. Please tell me what could be wrong.