Google test analytics: how to upload data via POST request

Trying Google test analytics to create a test plan I've read the guidelines for data posting at http://ift.tt/1Hajqbb.

It is said, that I need to upload data via submitting a POST request to the following URL:http://ift.tt/1CQLwST You will need to post a JSON array containing the data you would like to import.

However I can't simply Compose that request in Fiddler and send, since I need to authentificate first. Am I right that I need to set up the authetification for google and only then execute the POST request or there is another simplier way to process this POST request.