Вход через Facebook для iOS — быстрое начало работы

    
// AppDelegate.swift
import UIKit
import FacebookCore

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {    
    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {          
        ApplicationDelegate.shared.application(
            application,
            didFinishLaunchingWithOptions: launchOptions
        )

        return true
    }
          
    func application(
        _ app: UIApplication,
        open url: URL,
        options: [UIApplication.OpenURLOptionsKey : Any] = [:]
    ) -> Bool {
        ApplicationDelegate.shared.application(
            app,
            open: url,
            sourceApplication: options[UIApplication.OpenURLOptionsKey.sourceApplication] as? String,
            annotation: options[UIApplication.OpenURLOptionsKey.annotation]
        )
    }  
}

// SceneDelegate.swift
import FacebookCore
  ...
func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
    guard let url = URLContexts.first?.url else {
        return
    }

    ApplicationDelegate.shared.application(
        UIApplication.shared,
        open: url,
        sourceApplication: nil,
        annotation: [UIApplication.OpenURLOptionsKey.annotation]
    )
}