This is the safest method for beginners.
Older Apple devices like the iPhone 5s, iPhone 6, iPad Air, and iPad mini 2/3 are locked out of modern iOS updates. Their final operating system is iOS 12.5.7. If you try to download YouTube from the App Store on these devices, you will see a frustrating error message stating that the app requires iOS 14.0 or later. download youtube ios 1257 link
If you already have YouTube but it shows an "Update Required" screen that won't go away, community members often suggest these advanced (unsupported) steps: This is the safest method for beginners