Hi,
A number of people who are due for the free year of Apple TV+ have reported having difficulty seeing the offer. Two suggestions have worked sometimes - going to the website and signing in there: and one poster has reported that he had to sign in on the device he bought recently rather than older ones.
It's also been reported that Apple are giving people who haven't been able to do this a code to redeem, though they will require details of the qualifying purchase:
https://www.macrumors.com/2019/11/04/apple-tv-redeem-codes-1-year-free-trial/
Good to know there’s a redemption code to offer people.