AppDelegate_1.swift

import UIKit

final class AppDelegate: UIResponder, UIApplicationDelegate {
  func application(
    _ application: UIApplication,
    configurationForConnecting connectingSceneSession: UISceneSession,
    options: UIScene.ConnectionOptions
  ) -> UISceneConfiguration {
    let configuration = UISceneConfiguration(
      name: "Main Scene",
      sessionRole: connectingSceneSession.role
    )
    configuration.delegateClass = MainSceneDelegate.self
    return configuration
  }
}

ContentView_1.swift

import SwiftUI

struct ContentView: View {
  @State private var showComposeView = false
  
  var body: some View {
    Text("Hello, world!")
      .padding
      .alert(isPresented: $showComposeView) {
        Alert(
          title: Text("Compose Note"),
          message: Text("TODO: Compose a note"),
          primaryButton: .default(Text("Create")),
          secondaryButton: .cancel()
        )
      }
      .onOpenURL { url in
        guard url.path == "/createNote" else {
          return
        }
                
        showComposeView = true
      }
  }
}

MainSceneDelegate_1.swift

import SwiftUI
import UIKit

final class MainSceneDelegate: UIResponder, UIWindowSceneDelegate {
  @Environment(\.openURL) private var openURL: OpenURLAction
  
  func scene(
    _ scene: UIScene,
    willConnectTo session: UISceneSession,
    options connectionptions: UIScene.ConnectionOptions
  ) {
    guard let shortcutItem = connectionOptions.shortcutItem else {
      return
    }
    
    handleShortcutItem(shortcutItem)
  }
  
  func windowScene(
    _ windowScene: UIWindowScene,
    performActionFor shortcutItem: UIApplicationShortcutItem,
    completionHandler: @escaping (Bool) -> Void
  ) {
    handleShortcutItem(shortcutItem, completionHandler: completionHandler)
  }
  
  private func handleShortcutItem(
    _ shortcutItem: UIApplicationShortcutItem,
    completionHandler: ((Bool) -> Void)? = nil
  ) {
    guard shortcutItem.type == "me.michaelfcollins3.QuickActionDemo.CreateNoteAction" else {
      completionHandler(false)
      return
    }
    
    openURL(URL(string: "quickactiondemo://actions/createNote")!) { completed in
      completionHandler(completed
    }
  }
}

QuickActionDemoApp_1.swift

import SwiftUI

@main
struct QuickActionDemoApp: App {
  var body: some Scene {
    WindowGroup {
      ContentView()
    }
  }
}

QuickActionDemoApp_2.swift

import SwiftUI

@main
struct QuickActionDemoApp: App {
  @UIApplicationDelegateAdaptor private var appDelegate: AppDelegate
  
  var body: some Scene {
    WindowGroup {
      ContentView()
    }
  }
}