had to change entrypoint in Dockerfile

Dockerfile

@@ -19,4 +19,4 @@ RUN python scripts/download_model.py
 
 COPY . /app
 
-ENTRYPOINT gunicorn --bind 0.0.0.0:8000 --workers 1 --timeout 360 dash_app.app:server
+ENTRYPOINT gunicorn --bind 0.0.0.0:8000 --workers 1 --timeout 360 dash_app.index:server