@mungbeans Thanks you. This is work with UIKit, but i'm using swiftUI

Yes. majorVersion should be an integer. (12.0 10.16 = major.minor) But i don't know why MacOS Monterey Beta return 10.16 I just discovered: Xcode 11.7 => build version <= 10.15 => return version is correct, but version > 10.15 (BigSur..) => return 10.16. Xcode 12 build => return version is correct but MacOS Montery can not install the app