how do I add existing subscriptions to apple tv
Several of my existing streaming services no longer appear on my Apple TV app on my roku or on my Mac mini. How do I re-add them?
Your subscriptions are tied to your Apple Id, not a specific device.
If they are not showing in the Apple TV App, follow the steps here and check if they are still active: link-> How to see or cancel a subscription from Apple - Apple Support
If they appear there, but are not accessible in the TV App, try signing out and back in to the TV App.