403 is an Unauthorized Error. That means you lack sufficient permission to connect to the content at that server. I'm not sure if this could be due to the inability to fetch data from your hosting provider, but it could also be denied based on header information the remote server has flagged as unauthorized.
Try using the answer on this post: php curl: how can i emulate a get request exactly like a web browser? to curl the same data from the server that is getting the 403