as been blocked by CORS policy: Response to preflight request doesn't pass access control check: It does not have HTTP ok status. code example
Example: been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
My issue was the remote server not responding to OPTIONS requests,
so after fiddling about with requests and headers for what seemed
like ages I resolved it by removing the headers
Content-Type and Access-Control-Allow-Origin