Note on accuracy: Apple does not allow downloading specific old versions (like 1.5.7) directly from the App Store. The App Store always serves the latest compatible version for your iOS. If you need 1.5.7, it is typically because you are running iOS 13 or iOS 14 (which cannot run the modern GarageBand v2.3+).
. Apple does not provide standalone direct download links for specific older versions like iOS 15.7. garageband ios 157 download link
Tips and Tricks
There is no public "GarageBand 1.5.7 download link."
Use the App Store → Purchased method on an iOS 13/14 device. That is the only safe, legal, and working way. Note on accuracy: Apple does not allow downloading