The free one-year trial can be activated in the Apple TV app at launch on any qualifying Apple device. However, we've heard reports that some iPhone 11 owners aren't seeing the trial they're entitled to in the TV app.
If the trial isn't showing up for you on your device, here's a solution that appears to be working for many people.
Open a desktop web browser, go to https://tv.apple.com and log in using your Apple ID credentials. You should be able to accept the 1-year free trial offer from there. Then on your iPhone, sign out of the TV app, close it, then launch the app and sign in again.
Your one-year free Apple TV+ trial should hopefully now be active.
1-Year Subscription to Apple TV+ Offers Savings
Also today, Apple quietly added a one-year plan to its subscription options for the video streaming service.
A one-year Apple TV+ subscription offers a $9.89 annual saving over the $4.99 monthly plan (around a 15 percent discount). Users can select it without affecting their free one year trial by going to the Account section of the TV app: Manage Subscriptions -> Apple TV+.