• First you need create a new project

• Delete the file main from your project

• after that we will have to clean some properties where it refers to file main
• click on the symbol ➖ and delete the property Storyboard Name

• Access the main file, go to "build settings" and search about the reference "main"
• delete the value's property

• access the file scene delegate
• inside function "scene", we will add this code above

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
  guard let windowScene = (scene as? UIWindowScene) else { return }
  let window = UIWindow(windowScene: windowScene)
  let vc = ViewController()
  window.rootViewController = vc
  window.makeKeyAndVisible()
  self.window = window
}

To test if works it, access the viewController add this line inside the method viewDidLoad()

import UIKit

class ViewController: UIViewController {
  override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = .yellow
  }
}

Just execute and magic happens 🍏