social-app/apps/ios/Runner/AppDelegate.swift

import Flutter
import flutter_local_notifications
import UIKit
import UserNotifications

@main
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    FlutterLocalNotificationsPlugin.setPluginRegistrantCallback { registry in
      GeneratedPluginRegistrant.register(with: registry)
    }
    GeneratedPluginRegistrant.register(with: self)
    if #available(iOS 10.0, *) {
      UNUserNotificationCenter.current().delegate = self
    }
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}