JavaFX adding spots to linked list

For javafx code, I made a KeyEvent and a MouseEvent where the user clicks on the screen and a spot will appear (spot is an inner class that I defined), but how can I add each spot that appears on the screen into my dotList? I am not sure how to do that?

Java Code:

public void start(Stage stage) {
        dotList = new SinglyLinkedList<>();
        Pane root = new Pane();

        root.setOnMouseClicked(event ->
                root.getChildren().add(
                        new Spot(
                                event.getX(),
                                event.getY()                                
                        )
                )
        );        

        Scene scene = new Scene(root, SIZE, SIZE, Color.BLACK);
        scene.setOnKeyTyped(event -> {
            switch (event.getCharacter()) {
                case "1":
                    currentColor = Color.RED;
                    break;
                case "2":
                    currentColor = Color.BLUE;
                    break;
                case "3":
                    currentColor = Color.GREEN;
            }
        });

        stage.setScene(scene);
        stage.show();  
}