all based on Ubuntu 20.04

installation

# install npm
$ sudo apt install -y npm

starting new project (not needed)

$ npm init react-app client

npm commands

$ npm start
#    Starts the development server.

$ npm run build
#    Bundles the app into static files for production.

$ npm test
#    Starts the test runner.

$ npm run eject
#    Removes this tool and copies build dependencies, configuration files
#    and scripts into the app directory. If you do this, you can’t go back!