phaser animation on update event

preload ()
    {
        this.load.atlas('knight', 'assets/animations/knight.png', 'assets/animations/knight.json');
        this.load.image('bg', 'assets/skies/clouds.png');
        this.load.spritesheet('tiles', 'assets/tilemaps/tiles/fantasy-tiles.png', { frameWidth: 64, frameHeight: 64 });
    }

    create ()
    {
        //  The background and floor
        this.add.image(400, 16, 'bg').setOrigin(0.5, 0);

        for (let i = 0; i < 13; i++)
        {
            this.add.image(64 * i, 536, 'tiles', 1)
                .setOrigin(0);
        }

        //  Our flowers
        for (let i = 0; i < 8; i++)
        {
            const flower = this.add.image(500, 472 - (i * 52), 'tiles', 31).setOrigin(0);
            this.flowers.push(flower);
        }

        this.add.text(400, 8, 'Click to play. Update Event on frame0004', { color: '#ffffff' })
            .setOrigin(0.5, 0);

        //  Our attack animation
        const attackConfig = {
            key: 'attack',
            frames: this.anims.generateFrameNames('knight', { prefix: 'attack_B/frame', start: 0, end: 12, zeroPad: 4 }),
            frameRate: 16
        };

        this.anims.create(attackConfig);

        //  Our coin animation
        const coinConfig = {
            key: 'coin',
            frames: this.anims.generateFrameNumbers('tiles', { start: 42, end: 47 }),
            frameRate: 12,
            repeat: -1
        };
        this.anims.create(coinConfig);

        const lancelot = this.add.sprite(300, 536, 'knight', 'attack_C/frame0000')

        lancelot.setOrigin(0.5, 1);
        lancelot.setScale(8);

        //  Event handler for when the animation updates on our sprite
        lancelot.on(Phaser.Animations.Events.ANIMATION_UPDATE, function (anim, frame, sprite, frameKey) {
            //  We can run our effect when we get frame0004:
            if (frameKey === 'attack_B/frame0004')
            {
                this.releaseItem();
            }

        }, this);

        //  And a click handler to start the animation playing
        this.input.on('pointerdown', function () {
            lancelot.play('attack', true);
        });
    }

    releaseItem ()
    {
        if (this.flowers.length === 0)
        {
            return;
        }

        const flower = this.flowers.pop();
        this.tweens.add({
            targets: flower,
            x: 864,
            ease: 'Quad.out',
            duration: 500
        });
    }
Himanshu Jangid