Scene Key property type
This user property type allows any string values, but provides a dialog for selecting a scene key. This dialog shows all the scenes of the project and you can pick one. Then, its key is set as value.

The scene compiler generates Scene Key properties like this:
class GoToSceneButton extends Phaser.GameObjects.Sprite {
constructor(..) {
...
}
/** @type {string} */
jumpTo;
}
And the code it generates in the scene is like this:
// goToSceneButton (prefab fields)
goToSceneButton.jumpTo = "Level";