IPA files downloaded directly from the App Store are encrypted with your Apple ID. A DMG "conversion" won't bypass this; the app will still ask for the original purchaser’s credentials when opened.
: Simply putting an iOS app inside a Mac disk image does not make it run on a Mac unless the app is specifically built as a "Universal" app or you are using Apple Silicon (M1/M2/M3) 1. Technical Analysis of Formats IPA (iOS App Store Package) DMG (Apple Disk Image) Primary OS iOS, iPadOS, tvOS Compressed ZIP (contains Sector-based disk image (like a virtual USB) Requires Cocoa Touch environment Requires AppKit/macOS environment Encrypted via FairPlay (App Store) Typically unencrypted (unless FileVaulted) 2. When Conversion is Possible (and Why) ipa to dmg