ui/src/phaser3-rex-plugins/templates/spinner/cube/Factory.js

import Cube from './Cube.js';
import ObjectFactory from '../ObjectFactory.js';
import SetValue from '../../../plugins/utils/object/SetValue.js';

ObjectFactory.register('cube', function (config) {
    var gameObject = new Cube(this.scene, config);
    this.scene.add.existing(gameObject);
    return gameObject;
});

SetValue(window, 'RexPlugins.Spinner.Cube', Cube);

export default Cube;