How do I identify if a CORS error is the cause of my React/Axios request failing?

CORS errors often manifest as network errors in your browser's developer tools (usually under the 'Network' tab). Look for requests that are failing with a 403 Forbidden status code. The error message in the browser console will often include details about the missing CORS headers, such as `Access-Control-Allow-Origin`. Inspect the request headers in the Network tab to see if `Access-Control-Allow-Origin` is present and set to allow your React app's origin.