Missing CORS header

I'm trying to use this API as an alternative to restcountries.eu, but I'm getting a CORS error on my Chrome browser when trying to fetch inside my webpack dev server.

Access to XMLHttpRequest at 'https://restcountries.com/v2/all?fields=name,alpha2Code,flag,callingCodes' from origin 'http://localhost:3000' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Acessing the same URL directly works fine, though.