Flutter feature discovery - DescribedFeatureOverlay from right Side

Question

I'm using feature_discovery 0.13.0+2. I'm trying to show feature discovery from right side. for example the animation come from right side. Right now When I'm trying this the animation come from left side and cover the full screen.

 Scaffold(

      body: Container(
        alignment: Alignment.centerRight,
        child: DescribedFeatureOverlay(
          featureId: 'feature1',
          targetColor: Colors.white,
          textColor: Colors.black,
          backgroundColor: Colors.purpleAccent,
          contentLocation: ContentLocation.above,
          title: Text(
            'This is Button',
            style: TextStyle(fontSize: 20.0),
          ),
          pulseDuration: Duration(seconds: 1),
          enablePulsingAnimation: true,
          barrierDismissible: false,

          overflowMode: OverflowMode.extendBackground,
          openDuration: Duration(seconds: 1),
          description: Text('This is Button you can add more details heres'),
          tapTarget: Icon(Icons.radio_button_unchecked),
          child: RaisedButton(
            child: Text('Button'),
            onPressed: () {},
            color: Colors.green,
          ),
        ),
      ),
    )