Run the code :

    @Override
    public void start(Stage stage) throws Exception {
        SplitMenuButton b = new SplitMenuButton();
        b.setText("Text");
        b.setMinSize(100, 100);
        b.setTextAlignment(TextAlignment.RIGHT);///It is ignored
        stage.setScene(new Scene(b));
        stage.show();
    }

I asked right alignment, but text is still aligned on the left side (which is by default)