Hello Dede,
I've pulled down the code from github and ran it in production mode.
The only difference that I made in the source app was add a secrets key in the secrets.yml file and run the app with RAILS_ENV=production passenger start as this will mount the rails app under nginx (similar to how it would be on a production environment).
I was able to get the camera showing without any issues.
You may want to check your browser to ensure that the camera was shared.