For development, you'll have to export two environmental variables in order for authorization to work correctly. This can be easily done by adding a .env.local file in the root directory with the following:

REACT_APP_SPOTIFY_CLIENT_ID=YOUR-CLIENT-ID
REACT_APP_SPOTIFY_REDIRECT_URI=http://localhost:3000/callback

You can register for your own client ID on the Spotify Developers Site.

In the project directory, you can run:

Runs the app in the development mode.
Open http://localhost:3000 to view it in the browser.

The page will reload if you make edits.
You will also see any lint errors in the console.

Launches the test runner in the interactive watch mode.
See the section about running tests for more information.

This project was bootstrapped with Create React App.