I got this:
XMLHttpRequest cannot load http://62.244.120.89:9000/api/v2/content/categories/sl_1-main/. Request header field HTTP_LANGUAGE_CODE is not allowed by Access-Control-Allow-Headers in preflight response.
I found question: Request header field Access-Control-Allow-Headers is not allowed by itself in preflight response
In one answer they suggest to add response headers
response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Credentials", "true"); response.setHeader("Access-Control-Allow-Methods", "GET,HEAD,OPTIONS,POST,PUT"); response.setHeader("Access-Control-Allow-Headers", "Access-Control-Allow-Headers, Origin,Accept, X-Requested-With,
Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers");
Do I do this on server on client ?