Using SpreadShirt REST API with JavaScript / Fetch

I’ve built a simple app using ReactJS. Here, I use the JS Fetch API to make a REST call to SpreadShirt’s API.

Basically, I am not receiving any information. The following information is displayed in the browser’s console:

Access to fetch at '' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: It does not have HTTP ok status. 

Ahoy @User_EU-0ffd42e3,

could you explain what you want to achieve? I just checked your acocount and you dont have any designs in it yet. So is there an issue with the upload?

Unfortunately, I don’t know anything about programming, but when I understand your question better, I might be able to answer it.