FacebookAppDelegate.swift

import UIKit
import Firebase
import FBSDKCoreKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    
    var window: UIWindow?
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    
        FIRApp.configure()
        FBSDKApplicationDelegate.sharedInstance().application(application, didFinishLaunchingWithOptions: launchOptions)
    
        return true
 
    }
    
    func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
        
        let sourceApplication = options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String
        let annotation = options[UIApplicationOpenURLOptionsKey.annotation]
         return FBSDKApplicationDelegate.sharedInstance().application(app, open: url, sourceApplication: sourceApplication, annotation: annotation)
     
    }