is technically an older operating system, you can still download and work in GarageBand by following a specific "last compatible version" workaround if the current version requires iOS 17 or later. How to Get GarageBand on iOS 15.7

If you get the "GarageBand iOS 1.5.7 download work" error where the app installs but crashes on launch, turn on Airplane Mode . Disable Wi-Fi. The app is trying to phone home to an authentication server that no longer recognizes its signature. Offline, it boots in 2 seconds.

: Go to the App Store on the newer device, search for GarageBand, and tap "Get" . You do not need to fully install it; just starting the download links it to your account.