I am using the php code sample for uploading a video provided by youtube, which can be found here: https://developers.google.com/youtube/v3/code_samples/php#upload_a_video
However, when the session starts, it requires the user to authorise it, so it takes you to the authorise page, then redirects you back. On doing this, it uploads twice, I assume it is trying to upload the video it could not do when it was not authorised. It only double uploads when authorising, and not when the page is reloaded and the session is still valid.
How do I stop this initial duplicate upload?