origin has been blocked by CORS policy

when i am using box api i am facing issue origin has been blocked by CORS policy. i have added my domain in the configration CORS Domains.

complete error is  : Access to XMLHttpRequest at 'https://upload.box.com/api/2.0/files/content' from origin 'https://www.appcurry.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

and i am using this code : 

boxClient.files.upload({ body: formData })
.then(function (file) {
var newFile = file;
console.log(file);
})
.catch(function (err) {
console.log(err);
});