Get Twitch VOD source video URL

I'm building an application in Unity that can play Twitch VODs via the AVPro video player. Using Twitch's API (V5) I can retrieve up to 100 of the most recent VODs of a given channel.

However, the JSON objects contain URLs with only a link to the VOD (the same one you'd see if you went to a channel and clicked on an archived broadcast) and not a link to the video file itself. I have searched all over the internet and through Twitch's API and cannot find a way to get the URL to the video file corresponding to a VOD. To note, I am getting this data in C# using Unity's WWW class.

Is there something I'm missing, or is this simply not possible? All help is greatly appreciated!