Switching levels?

Phaser 3
1

so i’m trying to switch levels but i have a problem.

when i load the assets like this :

// Load Tileset for Level{s} { 1 }

this.load.image ( 'lvl-1', 'assets/tilesets/platformPack_tilesheet.png' );

// Load Tileset for Level{s} { 2 }

this.load.image ( 'lvl-2', 'assets/tilesets/platformPack_tilesheet-2.png' );

// Load Level { 1 }

this.__load.tilemapTiledJSON ( 'lvl-1', 'assets/tilemaps/levels/lvl-1.json' );

// Load Level { 2 }

this.__load.tilemapTiledJSON ( 'lvl-2', 'assets/tilemaps/levels/lvl-2.json' );

& use this class :

class LevelManager {

    constructor ( __scene ) {

        this.__scene = __scene;
        this.__level = 0;

        this.__data = [

            { enemies : 10, }, 
            { enemies : 20, }, 

        ];

    }

    nextLevel ( __scene, __sceneKey ) {

        this.__level++;

        this.__scene = __scene;
        this.__sceneKey = __sceneKey;

        this.__scene.scene.start (
            this.__sceneKey, 
            this.__data [ this.__level ]
        );

        if ( this.__level > 0 ) {
            console.log ( 'SCENE' + ' :: ' + ' { ' + '\'' + ( this.__level + 1 ) + '\'' + ' } ' + 'WITH' + ' ' + 'SCENE KEY' + ' ' + '::' + ' { ' + '\'' + this.__sceneKey + '\'' + ' } ' + 'HAS BEEN STARTED!' );
            console.log ( 'Data :: ' + '\r\n', this.__data [ this.__level ] );
        }

    }

}

& call it like this :

this.physics.add.overlap ( this.hero.sprite, this.__goal, function ( objectA, objectB )

{

    if ( ! ( this.__hasOverlapped ) )

    {

        // this.sound.play ( 'detach-camera' );
        // objectB.destroy ( );

        this.__level.nextLevel ( this, 'lvl-2' );

        this.__hasOverlapped = true;

    }

}, null, this );

i get a blank scene even though i load my tileset & JSON files for lvl-1 & lvl-2…

i just want it to switch & load my new JSON level.