please allow us to buy 4k movies specifcally

I was super excited to watch the movie aliens in 4K, but I can’t, because I already own the HD version. It was not automatically upgraded, and I do not even have the option to repurchase it. This problem has existed for a while and has been made even worse by the death of the iTunes Store. Please start Allowing us to purchase or re-purchase a movie in order to upgrade it to 4K. I appreciate that you do it for free sometimes, but it doesn’t always work. I would gladly pay money to upgrade it, but you don’t even give me that option. You sell a device called the Apple TV 4K. I own one. Please start being more specific about what is in 4K and what isn’t. Now I noticed that Apple TV is not even listed as one of the apps I can tag this question as and it still says iTunes Store. Please work on simplifying this.