How to expect a long response from the server?

Question

JavaScript

I send a fetch request, the Post method throws an error in a minute

Access to fetch at ' https://www.test.com:3999/api/test/ ' from origin ' localhost:3000 ' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.