Text on the page you linked says "the Account Holder of your Apple Developer Program and/or Apple Developer Enterprise Program can submit an entitlement request." When I follow the link I see "Your account can’t access this page. There may be certain requirements to view this content. You must be the Account Holder of an Apple Developer Program for Organizations or an Apple Developer Enterprise Program to view this page."

Update: Using an UnlitMaterial node instead of PreviewContent, with tone mapping disabled, gives a much more vivid render. See @Shengjiang's answer below.

You will get a better response if you start a new thread . This sample code looks like it will help you. I think it’s quite new. https://developer.apple.com/documentation/avfoundation/media_reading_and_writing/converting_side-by-side_3d_video_to_multiview_hevc