Adding initialization code on iOS

AppDelegate.cs

[Register("AppDelegate")]
public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
{
  public override bool FinishedLaunching(UIApplication app, NSDictionary options)
  {
    global::Xamarin.Forms.Forms.Init();
    
    // Add this...
    ZXing.Net.Mobile.Forms.iOS.Platform.Init();
    
    LoadApplication(new App());

    return base.FinishedLaunching(app, options);
  }
}