a cross-origin error. This is because of the same-origin policy, which is a security feature implemented in web browsers to prevent web pages from making requests to a different domain than the one that served the web page.

If you are seeing a cross-origin error when trying to make a request from a React app, it means that the server you are trying to make a request to is on a different domain than your React app.

There are a few ways to handle this error:

1. You can set up a proxy server to act as a middleman between your React app and the server you are trying to make a request to. This way, your React app will make a request to the proxy server, which will then forward the request to the server on the different domain.

2. You can also use the CORS (Cross-Origin Resource Sharing) headers on the server you are trying to make a request to. These headers allow the server to specify which domains are allowed to make requests to it.

3. If you have control over the server you are trying to make a request to, you can also consider serving your React app from the same domain as the server. This will eliminate the need for cross-origin requests and the associated error.

It’s important to note that the same-origin policy is in place to protect against malicious attacks and should not be disabled unless absolutely necessary.