Crhomrcasting a Ruby app (using Android Chromecast App) hosted in AWS is not working

Created a Ruby app. I'm able to chromecast using chrome browser. I have deployed it in Heroku and able to Chromecast using ChromeCast app (Android0 and it worked. When I deployed in AWS and using its public DNS URL, I'm trying to cast using Android Chromecast App its casting...but I see dark background only. Any ideas?