Google Maps for Flutter iOS Swift setup

You can add your API key as follows:

AppDelegate.swift:

import UIKit
import Flutter
import GoogleMaps // Add this line!

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)
    GMSServices.provideAPIKey("YOUR_API_KEY")  // Add this line!
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

One more thing, Dont forget to add below line on ios/Runner/Info.plist

<key>io.flutter.embedded_views_preview</key>
<true/>