Set up an interceptor for handling errors. You can use it to fire a notification toast to notify users that something went wrong, log out unauthorized users, or send new requests for refreshing tokens.
API Errors Notification Example Code
Use error boundaries to handle errors that happen in the React tree. It is very popular to set only 1 single error boundary for the entire application, which would break the entire application when an error occurs. That's why you should have more error boundaries on more specific parts of the application. That way if an error occurs the app will still work without the need to restart it.
You should track any errors that occur in production. Although it's possible to implement your own solution, it is a better idea to use tools like Sentry. It will report any issue that breaks the app. You will also be able to see on which platform, browser, etc. did it occur. Make sure to upload source maps to sentry to see where in your source code did the error happen.