TrueView video discovery ads run on:
- The Search Network and the Display Network
- The YouTube Network
- YouTube videos and YouTube search pages
- The Display Network
Explanation:
TrueView Video Discovery ads appear on YouTube-related videos search results pages; the video opens on a YouTube watch or channel page, Video partner sites and apps on the GDN
Read more here: https://support.google.com/adwordspolicy/answer/2679940?hl=en
https://www.youtube.com/watch?v=2bp51KETzoY
