how to add shadow to a rectangle element using scenegraph and brs

I have a rectangle element -

<rectangle
            height= "90"
            width = "1920"
            color="#f5f5f5"
        />

how to add a shadow like effect to it.

Add another rectangle before it in your XML with whatever offset you want.

<rectangle
  height= "90"
  width = "1920"
  color="#f5f5f5"
  translation="[10,10]"
  opacity="0.80"
/>

You’ll probably want to experiment with color, translation, and opacity to get the effect you desire.