Install Node v8.9.1 or later and place its bin directory into your path. Be sure to include the npm library manager.
https://nodejs.org/en/download/
cd SmartOnFHIRClientDemo/
npm install
Run npm start for a dev server. Navigate to http://localhost:8080/. The app will automatically reload if you change any of the source files.
npm build
or
npm run-script build