How to fix iOS crash during the start Firebase configure in Flutter?

If you see this kind of error log, read continue

Logs

Launching lib/main.dart on iPhone X in debug mode...
Running Xcode clean...                                       1.1s
Starting Xcode build...
 ├─Assembling Flutter resources...                    1.7s
 └─Compiling, linking and signing...                  7.8s
Xcode build done.                                           15.4s
4.13.0 - [Firebase/Core][I-COR000003] The default Firebase app has not yet been configured. Add `[FIRApp configure];` (`FirebaseApp.configure()` in Swift) to your application initialization. Read more: https://goo.gl/ctyzm8.
*** First throw call stack:
(
	0   CoreFoundation                      0x0000000106a3c1e6 __exceptionPreprocess + 294
	1   libobjc.A.dylib                     0x00000001060d1031 objc_exception_throw + 48
	2   CoreFoundation                      0x0000000106ab1975 +[NSException raise:format:] + 197
	3   Runner                              0x0000000101e3336a +[FIRApp configure] + 352
	4   Runner                              0x0000000101eeef49 -[FLTFirebaseAnalyticsPlugin init] + 185
	5   Runner                              0x0000000101eeee28 +[FLTFirebaseAnalyticsPlugin registerWithRegistrar:] + 168
	6   Runner                              0x0000000101d9723c +[GeneratedPluginRegistrant registerWithRegistry:] + 124
	7   Runner                  <…>

Step 1: Remove the GoogleService-Info.plist file if you have already in the project and follow all these steps. Don’t miss out.

Step 2: Open Runner.xcworkspace instead of Runner.xcodeproj in XCode, then add the file under Runner directly. (Only load the ios/Runner with Xcode). Just’s copy and paste in folder not working well.

Step 3: You need to place this code

FirebaseApp.configure()

before this one

GeneratedPluginRegistrant.register(with: self)

you will see in AddDelegate.swiftlike this.

import UIKit
import Flutter
import Firebase

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    FirebaseApp.configure()
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

After this, you will be fixed.