CORS error with react/node/webpack

I have installed raven via npm and are trying to send error but get the following error in the browser:

XMLHttpRequest cannot load https://sentry.io/api/******/store/. Response to preflight request doesn’t pass access control check: Credentials flag is ‘true’, but the ‘Access-Control-Allow-Credentials’ header is ‘’. It must be ‘true’ to allow credentials. Origin ‘https://MYDOMAIN.com’ is therefore not allowed access.

Is this in a hybrid or mobile app? If so, you might need to use your private DSN.

If this is a regular website, check that your “Allowed Origins” project setting includes the domain you’re transmitting from.

If none of those help, could you post the HTTP response message?