Apple does not officially provide a standalone DMG installer for this specific version; it is distributed exclusively through the Mac App Store. How to Download GarageBand 10.3.5

: Resolved issues where "Audio file not found" alerts appeared unexpectedly after deleting and saving projects [5.4]. Troubleshooting Common Issues "Incompatible Version" Error

Usually requires macOS 10.13.6 (High Sierra) or 10.14 (Mojave) .