About: xhr.setRequestHeader( 'Api-User-Agent', 'Example/1.0' );
Failed to load https://en.wikipedia.org/w/api.php?action=query&prop= :links&format=json&titles= Bulgaria&callback=JSON_ CALLBACK Response to preflight request doesn't pass access control check:No 'Access-Control-Allow-Origin' header is present on the requested resource.Origin 'https://s.codepen.io' is therefore not allowed access.