Already subscribed to an app (EXPIC) how do I add it to Apple TV channels

If I subscribe through Apple TV channels it creates 2 subscriptions and it appears I will get billed twice, once for the channels subscription and the other for the APP subscription. My app subscription is paid via my apple account and linked in my Apple TV in subscriptions. The same as the Apple TV channels subscription.

Does one just cancel the other I will not get billed twice? I do not see an option on my Apple TV to sign into the channel, it just asked if I want a free trail and want to subscribe, thus creating two subscriptions.