I have a built a small React application with create-react-app, and it runs fine from the local server after running npm start. OK so far.
npm start
After building your application through create-react-app create-react-app
create-react-app
Run command npm run build After that run command npm install -g serve & finally serve -s build
npm run build
npm install -g serve
serve -s build
More detailed information can be found from here create-react-app-deployment