Apple TV 1 year subscription not showing

Please ensure you followed the instructions:

Turn on your new Apple device and sign in with your Apple ID

Open the Apple TV app. Make sure your device is running the latest version of iOS, iPadOS, tvOS, or macOS.

The offer should be presented immediately after launching the app. If not, go to the Apple TV+ channel page, signed in, where you’ll see the offer.

Tap Enjoy 1 Year Free.

Apple TV + Offer

https://support.apple.com/en-us/HT210573

Offer must be claimed within 90 days from when you activated the new device 

Your new device must also be capable of running the latest iOS, iPadOS, tvOS, or macOS. Offer cannot be combined with other free trials or offers for Apple TV+.

If you are within the 3 month period and are not seeing the offer after following the steps then contact Apple for assistance.

Then you will need to Contact Support