Apple TV free 3 months after iphone purchase

I recently purchased a new iPhone and therefore get 3 months free of Apple TV + service. Problem I am having is that I already have the app downloaded from when I purchased an iPad last year and received several free months of Apple TV+, and I see nothing on either my iPad or my iPhone in the Apple TV + app that allows me to select the free service for 3 months due to my recent purchase. I removed the app and reinstalled, but nothing changed. What steps do I take to begin my free 3 months? Surely someone else has had this issue before? Thanks if anyone can help.