Unable to see a single video from Apple TV . When I select a video to watch, I get a message that says "Video Not Available". I stream videos from Amazon and Disney and this Apple TV app is the most trouble. What is wrong?

Unable to see a single video from Apple TV+ using my Roku Ultra 4660X. When I select a program to watch, I get a message "Video Not Available". I've deleted the Apple TV app from the Roku, restarted the Roku, then added the Apple TV app back to the Roku (as directed by Roku customer support), but nothing seems to work. I even checked to be sure I had the most current software loaded on my Roku Ultra 4660X and it was up-to-date. I have no problem viewing programs from Amazon Prime or Disney Plus using my Roku Ultra 4660X, but NOTHING from Apple TV+. Why is Apple TV+ so difficult to use?