To tell the React development server to proxy any unknown requests to your node API server in development, you can add a proxy field to your client package.json, for example:
"proxy": "http://localhost:5000"
which will redirect all traffic to node API and not REACT Development URL.
This way, when you fetch('/api/articles') in development, the development server will recognize that it’s not a static asset, and will proxy your request to http://localhost:5000/api/articles as a fallback.