• Make sure you have docker installed on local machine
• run docker-compose-up
• check that flask server is up by going to http://localhost:5000/api
• Navigate to http://localhost:3000/ on the browser.

If you see this:

npm ERR! [email protected] start: `react-scripts start`
npm ERR! spawn ENOENT

It just means something went wrong when dependencies were installed the first time.

I suggest doing these three steps:

• npm install -g npm@latest to update npm because it is sometimes buggy.
• rm -rf node_modules to remove the existing modules.
• npm install to re-install the project dependencies.

Source - Here By Dan Abramov