The full movie of May Fairy Tail Love Story could be accessible on subscription-based services such as Hulu or Disney+. Another option is to search on legitimate online movie rental stores.
You might be able to find it on popular streaming platforms like Netflix or Amazon Prime Video. Check those first.
Well, sometimes it's available on dedicated movie streaming websites. But be careful as some of them might not be legal or of good quality. You could also try looking in your local cinema if it's still being shown.