Try:
this.game.scene.add('Scene', MyScene, true);
let cor = this.game.scene.getScene('Scene');
https://photonstorm.github.io/phaser3-docs/Phaser.Scenes.SceneManager.html#getScene
Try:
this.game.scene.add('Scene', MyScene, true);
let cor = this.game.scene.getScene('Scene');
https://photonstorm.github.io/phaser3-docs/Phaser.Scenes.SceneManager.html#getScene