How to use the babylonjs-gui.Button3D function in babylonjs-gui

create(scene: Scene): BabylonButton3D {
    this.button3D = new BabylonButton3D(this.props.name)

    // console.log("created button", this.props.name)

    let text: TextBlock | undefined = undefined
    let image: BabylonImage | undefined = undefined

    if (this.props.imageUrl) {
      image = new BabylonImage(`${this.props.name}-image`, this.props.imageUrl)
    }

    if (this.props.text) {
      text = new TextBlock()

      text.text = this.props.text
      if (this.props.fontColor) {
        text.color = this.props.fontColor.toHexString()

var startGameButton = function (panel) {
    var button = new GUI.Button3D();
    panel.addControl(button);
    button.onPointerUpObservable.add(function () {
        //reset score
        updateScore(0);
        addSpheres(scene);
        button.isVisible = false;
    });
    var text1 = new GUI.TextBlock();
    text1.text = "Start Game";
    text1.color = "white";
    text1.fontSize = 24;
    button.content = text1;
}
var scene: Scene = createScene();