I'm trying to make a SwiftUI created on Xcode 13 work on Xcode 11 (or iOS 13).

There's a similar post here but the suggestions doesn't seem to work on Xcode 11.

My current entrypoint looks like:

@main  // <- this does not work on Xcode 11!
struct MyAppWrapper {
    static func main() {
        if #available(iOS 14.0, *) {
            MyApp.main()
        } else {
            UIApplicationMain(CommandLine.argc, CommandLine.unsafeArgv, nil, NSStringFromClass(AppDelegate.self))
        }
    }
}

@available(iOS 14.0, *)
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

As in the comment above, Xcode 11 doesn't support @main. I would like to use AppDelegate for iOS 13, but use Scene and WindowsGroup method on iOS 14 and above.

I can't believe making a SwiftUI project that works across iOS 13~15 is this difficult..

What else can I try?

Update

Info.plist:

MyApp.swift:

AppDelegate.swift:

SceneDelegate.swift: