Yes, you have to Delete the storyboard file and delete the NSExtensionMainStoryboard property and add NSExtensionPrincipalClass that will be the class MessagesViewController and this your MSMessagesAppViewController. Add to your code @objc(MessagesViewController) In viewDidLoadMethod insert // Get the UIKit view of your SwiftUI View let child = UIHostingController(rootView: SwiftUIView()) self.view.addSubview(child.view) // Set the place where your view will be displayed let constraints = [             child.view.topAnchor.constraint(equalTo: view.topAnchor),             child.view.bottomAnchor.constraint(equalTo: view.bottomAnchor),             child.view.leadingAnchor.constraint(equalTo: view.leadingAnchor),             child.view.trailingAnchor.constraint(equalTo: view.trailingAnchor),             child.view.widthAnchor.constraint(equalTo: view.widthAnchor),             child.view.heightAnchor.constraint(equalTo: view.heightAnchor) ] view.addConstraints(constraints) Hope it will help you !