If you're using react you need to build the app for production before being deployed.

1. npm run build

2. Add this to the top of your package.json: "homepage": "https://.github.io/"

3. npm run build

4. npm install --save gh-pages

5. Add these scripts to your json:

"scripts": { "predeploy": "npm run build", "deploy": "gh-pages -d build" }

6. npm run deploy

7. Have a look at your deployed app 👌