Switching Tileset Textures

class Example extends Phaser.Scene
{
    currentTileset = 1;
    showDebug = false;
    player;
    helpText;
    debugGraphics;
    cursors;
    map;

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
        this.load.image('tiles', 'assets/tilemaps/tiles/catastrophi_tiles_16.png');
        this.load.image('tiles_red', 'assets/tilemaps/tiles/catastrophi_tiles_16_red.png');
        this.load.image('tiles_blue', 'assets/tilemaps/tiles/catastrophi_tiles_16_blue.png');
        this.load.tilemapCSV('map', 'assets/tilemaps/csv/catastrophi_level2.csv');
        this.load.spritesheet('player', 'assets/sprites/spaceman.png', { frameWidth: 16, frameHeight: 16 });
    }

    create ()
    {
        // When loading a CSV map, make sure to specify the tileWidth and tileHeight
        this.map = this.make.tilemap({ key: 'map', tileWidth: 16, tileHeight: 16 });
        const tileset = this.map.addTilesetImage('tiles_red');
        const layer = this.map.createLayer(0, tileset, 0, 0);
        layer.setScale(2);

        //  This isn't totally accurate, but it'll do for now
        this.map.setCollisionBetween(54, 83);

        this.input.keyboard.on('keydown-ONE', function (event)
        {
            const texture = this.sys.textures.get('tiles_red');
            this.currentTileset = 1;
            tileset.setImage(texture);
            this.updateHelpText();
        }, this);

        this.input.keyboard.on('keydown-TWO', function (event)
        {
            const texture = this.sys.textures.get('tiles_blue');
            this.currentTileset = 2;
            tileset.setImage(texture);
            this.updateHelpText();
        }, this);

        this.input.keyboard.on('keydown-THREE', function (event)
        {
            const texture = this.sys.textures.get('tiles');
            this.currentTileset = 3;
            tileset.setImage(texture);
            this.updateHelpText();
        }, this);


        this.anims.create({
            key: 'left',
            frames: this.anims.generateFrameNumbers('player', { start: 8, end: 9 }),
            frameRate: 10,
            repeat: -1
        });
        this.anims.create({
            key: 'right',
            frames: this.anims.generateFrameNumbers('player', { start: 1, end: 2 }),
            frameRate: 10,
            repeat: -1
        });
        this.anims.create({
            key: 'up',
            frames: this.anims.generateFrameNumbers('player', { start: 11, end: 13 }),
            frameRate: 10,
            repeat: -1
        });
        this.anims.create({
            key: 'down',
            frames: this.anims.generateFrameNumbers('player', { start: 4, end: 6 }),
            frameRate: 10,
            repeat: -1
        });

        this.player = this.physics.add.sprite(100, 100, 'player', 1)
            .setScale(2);
        this.player.setSize(10, 10, false);

        // Set up the player to collide with the tilemap layer. Alternatively, you can manually run
        // collisions in update via: this.physics.world.collide(player, layer).
        this.physics.add.collider(this.player, layer);

        this.cameras.main.setBounds(0, 0, this.map.widthInPixels, this.map.heightInPixels);
        this.cameras.main.startFollow(this.player);

        this.debugGraphics = this.add.graphics();

        this.input.keyboard.on('down_67', event =>
        {
            this.showDebug = !this.showDebug;
            this.drawDebug();
        });

        this.cursors = this.input.keyboard.createCursorKeys();

        this.helpText = this.add.text(16, 16, '', {
            fontSize: '20px',
            fill: '#ffffff'
        });
        this.helpText.setScrollFactor(0);
        this.updateHelpText();
    }

    update (time, delta)
    {
        this.player.body.setVelocity(0);

        // Horizontal movement
        if (this.cursors.left.isDown)
        {
            this.player.body.setVelocityX(-200);
        }
        else if (this.cursors.right.isDown)
        {
            this.player.body.setVelocityX(200);
        }

        // Vertical movement
        if (this.cursors.up.isDown)
        {
            this.player.body.setVelocityY(-200);
        }
        else if (this.cursors.down.isDown)
        {
            this.player.body.setVelocityY(200);
        }

        // Update the animation last and give left/right animations precedence over up/down animations
        if (this.cursors.left.isDown)
        {
            this.player.anims.play('left', true);
        }
        else if (this.cursors.right.isDown)
        {
            this.player.anims.play('right', true);
        }
        else if (this.cursors.up.isDown)
        {
            this.player.anims.play('up', true);
        }
        else if (this.cursors.down.isDown)
        {
            this.player.anims.play('down', true);
        }
        else
        {
            this.player.anims.stop();
        }
    }

    drawDebug ()
    {
        this.debugGraphics.clear();

        if (this.showDebug)
        {
            // Pass in null for any of the style options to disable drawing that component
            this.map.renderDebug(this.debugGraphics, {
                tileColor: null, // Non-colliding tiles
                collidingTileColor: new Phaser.Display.Color(243, 134, 48, 200), // Colliding tiles
                faceColor: new Phaser.Display.Color(40, 39, 37, 255) // Colliding face edges
            });
        }

        this.updateHelpText();
    }

    updateHelpText ()
    {
        this.helpText.setText(
            `Arrow keys to move.\nPress 1/2/3 to change the tileset texture.\nCurrent texture: ${this.currentTileset}`
        );
    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.WEBGL,
    width: 800,
    height: 600,
    backgroundColor: '#2d2d2d',
    parent: 'game-container',
    pixelArt: true,
    physics: {
        default: 'arcade',
        arcade: { gravity: { y: 0 } }
    },
    scene: Example
};

const game = new Phaser.Game(config);