Nginx CORS error

Request header field Access-Control-Allow-Headers is not allowed by Access-Control-Allow-Headers

add these lines in server part of the config file

   add_header 'Access-Control-Allow-Origin' * always;

        add_header 'Access-Control-Allow-Headers' * ;

xmlhttprequest-ajax-set-content-type

 location ~* \.(?:ico|css|js|gif|jpe?g|png|woff|application/json)$ {

            try_files $uri @blogcssjs;

            expires 30d;

            add_header 'Access-Control-Allow-Origin' * always;

            add_header Pragma public;

            add_header Cache-Control "public";

        }