Deployment
yarn buid or npm run build creates a build directory with a production build of your app. Set up your favourite HTTP server so that a visitor to your site is served index.html, and requests to static paths like /static/js/main.<hash>.js are served with the contents of the /static/js/main.<hash>.js file.
For more information visit create-react-app
For deploying your site in firebase visit Firebase Deployment page