I noticed Watrhub is asking for this. I'm not exactly sure what this means. Do I need to have been the head product manager for the product that I was launching?

Thx.

While you should definitely have seen a product from inception to launch, it's OK if you didn't actually run or own the process. The goal is to really showcase your experience here. More broadly, if you can tell a good story of how you observed or came up with features, user stories, etc. and then oversaw their actual implementation, then you'll be in a good spot!