Hi @Pavan_sai_Sheshetti, it looks like your application is trying and failing to open a video source with opencv in line 50: cap = cv2.VideoCapture(0) .
The app will work on your local machine as the “server” and “client” are identical. However, if you deploy your app on a remote server (including Streamlit Sharing), opencv will not be able to find the video source (webcam) as none exists.
You will need to use a component to get your users’ webcam feed. @whitphx is the creator of the 
awesome streamlit-webrtc component for real-time video processing. You should be able to use streamlit-webrtc to capture frames from users’ webcam feed and then process them with tools like opencv.
Happy Streamlit-ing! 
Snehan