Sundance Now

Please explain to me why last night I wanted to watch the next episode of Discovery of Witches I had to subscribe to Sundance Now (with a free month trial) before I could get Episode 6 to play. I thought Sundance Now was part of Apple TV and included in our subscription. If this is correct please tell me how I can get access to Sundance Now without subscribing to each time I want to watch something in their catalog. This is ver confusing and I really would like some clarification.

Thank you