Adding a channel
I subscribed to Peacock TV through them directly as they were offering a special price.
I download the app on my Apple TV and there is no where to sign in, it just gives me the option to subscribe.
I just need to sign in to the app that I have already subscribed to.
I notice this a lot with Apple TV. I have a Roku system in an other room and never have this issue.
Apple TV 4K (2nd generation)