When you go into settings 'Users and Accounts' is the second item (as you can see from my screenshot). It will be such on any modern Apple TV, running TVOS. The only reason you wouldn't see it is if you had an older model, like a 3rd gen. If you have a 4th gen or later make sure it is up to date.
In the meantime you could also check your account on iPad, if you can't see it there either then that means you do not have a current active subscription. However, if you do then you can contact Apple support to investigate further.
