Yesterday, Apple released iOS 12.5.1 for older devices that cant be updated to iOS 13 and iOS 14. Those devices include the original iPad Air, iPad mini 2 and iPad mini 3 as well as the iPhone 5s and iPhone 6, among others. This new update only addresses a bug that was introduced with the previous update to iOS 12, with iOS 12.5 last month.
That updated added Exposure Notifications and this update yesterday just addresses a display bug related to languages.
If you have an older device running iOS 12, you can update by going to Settings > General > Software Update