@conath reply works great only fix "deadline": @main struct ArabicForKidsMacApp: App { var body: some Scene { WindowGroup { ContentView() .onAppear { DispatchQueue.main.asyncAfter(deadline: .now()) { if let window = NSApplication.shared.windows.last { window.toggleFullScreen(nil) } } } } } }

It did not work for me and I solved it using "PostScript name" that can be obtained by installing the font on the mac and obtaining information specifically about the font in question in "Font Book"