Apple TV 1 year free - setup help

Hi! I activated my 1 year of Apple TV for free, but when I go to watch shows on my phone it directs me to HBO of Hulu (which I don’t have subscriptions for). I’ll select to play a show and then it tells me to choose an app to open that show in. I don’t really understand why I would need to access Apple TV from another app? That would mean I have to pay for a subscription to another app jut to watch something that was free with the subscription? I’m just a bit perplexed, I appreciate your assistance.