When I open the app everything works fine but when i close it and reopen it from the home screen it crashes on TestFlight.

Here's the crash log of the thread its crashing on:

Thread 0 name:
Thread 0 Crashed:
0   libswiftCore.dylib            	0x00000001847363fc _assertionFailure(_:_:file:line:flags:) + 264 (AssertCommon.swift:144)
1   PurchasesHybridCommon         	0x00000001019af1a4 closure #1 in variable initialization expression of static FatalErrorUtil.defaultFatalErrorClosure + 64 (FatalErrorUtil.swift:15)
2   PurchasesHybridCommon         	0x00000001019a73a0 fatalError(_:file:line:) + 60 (FatalErrorUtil.swift:27)
3   PurchasesHybridCommon         	0x00000001019a73a0 static CommonFunctionality.sharedInstance.getter + 84 (CommonFunctionality.swift:21)
4   PurchasesHybridCommon         	0x00000001019a73a0 static CommonFunctionality.customerInfo(fetchPolicy:completion:) + 84 (<compiler-generated>:405)
5   PurchasesHybridCommon         	0x00000001019a73a0 specialized static CommonFunctionality.customerInfo(completion:) + 372 (CommonFunctionality.swift:398)
6   PurchasesHybridCommon         	0x00000001019a3964 @objc static CommonFunctionality.restorePurchases(completion:) + 76
7   purchases_flutter             	0x0000000102cf5f2c -[PurchasesFlutterPlugin getCustomerInfoWithResult:] + 48 (PurchasesFlutterPlugin.m:347)
8   purchases_flutter             	0x0000000102cf493c -[PurchasesFlutterPlugin handleMethodCall:result:] + 2048 (PurchasesFlutterPlugin.m:100)
9   Flutter                       	0x000000010342196c 0x102e40000 + 6166892
10  Flutter                       	0x0000000102e83c00 0x102e40000 + 277504
11  libdispatch.dylib             	0x00000001933106a8 _dispatch_call_block_and_release + 32 (init.c:1530)
12  libdispatch.dylib             	0x0000000193312300 _dispatch_client_callout + 20 (object.m:561)
13  libdispatch.dylib             	0x0000000193320998 _dispatch_main_queue_drain + 984 (queue.c:7813)
14  libdispatch.dylib             	0x00000001933205b0 _dispatch_main_queue_callback_4CF + 44 (queue.c:7973)
15  CoreFoundation                	0x000000018b34cf9c __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 16 (CFRunLoop.c:1780)
16  CoreFoundation                	0x000000018b349ca8 __CFRunLoopRun + 1996 (CFRunLoop.c:3149)
17  CoreFoundation                	0x000000018b3493f8 CFRunLoopRunSpecific + 608 (CFRunLoop.c:3420)
18  GraphicsServices              	0x00000001ce8d74f8 GSEventRunModal + 164 (GSEvent.c:2196)
19  UIKitCore                     	0x000000018d76f8a0 -[UIApplication _run] + 888 (UIApplication.m:3685)
20  UIKitCore                     	0x000000018d76eedc UIApplicationMain + 340 (UIApplication.m:5270)
21  Runner                        	0x000000010030877c main + 64 (AppDelegate.swift:7)
22  dyld                          	0x00000001ae09edcc start + 2240 (dyldMain.cpp:1269)

this is my main.dart code:

import 'dart:io';

import 'package:awesome_notifications/awesome_notifications.dart';
import 'package:firebase_crashlytics/firebase_crashlytics.dart';
import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:presentpal/api/constants.dart';
import 'package:presentpal/api/firebase_api.dart';
import 'package:presentpal/api/purchases_api.dart';
import 'package:presentpal/pages/gift_chose.dart';
import 'package:presentpal/pages/home.dart';
import 'package:presentpal/provider/locale_provider.dart';
import 'package:presentpal/services/analytics_service.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'provider/theme_provider.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import 'services/preferences_service.dart';
import 'pages/change_notifier.dart' as presentpal;
import 'package:provider/provider.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:google_mobile_ads/google_mobile_ads.dart';
import 'pages/onboarding.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'store_config.dart';
import 'package:purchases_flutter/purchases_flutter.dart';
import 'package:presentpal/services/set_notifications.dart';
import 'package:timezone/data/latest.dart' as tz;

final navigatorKey = GlobalKey<NavigatorState>();


Future<void> configureLocalTimeZone() async {
  tz.initializeTimeZones();
}

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  presentpal.AppState appState = presentpal.AppState();
  try {
    MobileAds.instance.initialize();

    //get user data
    await Firebase.initializeApp();

    FlutterError.onError = (errorDetails) {
      FirebaseCrashlytics.instance.recordFlutterFatalError(errorDetails);
    };

    await FirebaseApi().initNotifications();

    await setNotifications.initializeNotifications();

    await configureLocalTimeZone();

    String? initialLocale = await getLocale();
    if (initialLocale != null && initialLocale.isNotEmpty) {
      appState.setLocale(initialLocale);
    }
    try {
      await dotenv.load(fileName: ".env");
    } catch (e) {
      print(e.toString());
    }
    if (Platform.isIOS) {
      StoreConfig(
        store: Store.appStore,
        apiKey: appleApiKey,
      );
    } else if (Platform.isAndroid) {
      StoreConfig(
        store: Store.playStore,
        apiKey: googleApiKey,
      );
    }
    await PurchaseApi.init();
  } catch (e) {
    print(e.toString());
    AnalyticsService analyticsService = AnalyticsService();
    analyticsService.logEvent('error: ${e.toString()}');
  }

  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (_) => LocaleModel()),
      ],
      child: MyApp(appState: appState),
    ),
  );
}

class MyApp extends StatefulWidget {
  final presentpal.AppState appState;

  const MyApp({super.key, required this.appState});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  bool hasSeenOnboarding = false;

  @override
  void initState() {
    super.initState();
    _populateFields();
    checkOnboardingStatus();
    AwesomeNotifications().isNotificationAllowed().then((isAllowed) {
      if (!isAllowed) {
        AwesomeNotifications().requestPermissionToSendNotifications();
      }
    });
  }

  Future<void> checkOnboardingStatus() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    final bool seenOnboarding = prefs.getBool('hasSeenOnboarding') ?? false;
    setState(() {
      hasSeenOnboarding = seenOnboarding;
    });
  }

  final _preferenceServices = PreferencesService();

  String selectedLanguage = 'en';

  void _populateFields() async {
    final settings = await _preferenceServices.getSettings();
    String? storedLanguage = settings.languageCode;
    if (storedLanguage.isNotEmpty) {
      setState(() {
        selectedLanguage = storedLanguage;
      });
      widget.appState.setLocale(selectedLanguage);
    } else {
      String languageCode;
      try {
        //get locale from settings
        Locale userLocale = WidgetsBinding.instance.window.locale;
        languageCode = userLocale.languageCode;
        if ([
          'en',
          'ar',
          'bn',
          'de',
          'es',
          'fr',
          'hi',
          'it',
          'ko',
          'pt',
          'ru',
          'zh',
          'zh_HK'
        ].contains(languageCode)) {
          setState(() {
            selectedLanguage = languageCode;
          });
          widget.appState.setLocale(selectedLanguage);
        }
      } catch (e) {
        languageCode = 'en';
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
        create: (context) => LocaleProvider(),
        builder: (context, child) {
          final provider = Provider.of<LocaleProvider>(context);
          return MaterialApp(
            debugShowCheckedModeBanner: false,
            title: 'PresentPal',
            themeMode: ThemeMode.system,
            theme: MyThemes.lightTheme,
            navigatorObservers: [AnalyticsService().getAnalyticsObserver()],
            navigatorKey: navigatorKey,
            locale: provider.locale,
            supportedLocales: const [
              Locale('en'), // English
              Locale('ar'), //Arabic
              Locale('bn'), //Bengali
              Locale('de'), //German
              Locale('es'), //Spanish
              Locale('fr'), //French
              Locale('hi'), //Hindi
              Locale('it'), //Italian
              Locale('ko'), //Korean
              Locale('pt'), //Portuguese
              Locale('ru'), //Russian
              Locale('zh'), //Chinese
              Locale('zh_HK') //Chinese (Hong Kong)
            ],
            localizationsDelegates: const [
              AppLocalizations.delegate,
              GlobalMaterialLocalizations.delegate,
              GlobalWidgetsLocalizations.delegate,
              GlobalCupertinoLocalizations.delegate,
            ],
            darkTheme: MyThemes.darkTheme,
            routes: {
              '/home': (context) => const HomePage(),
              '/onboarding': (context) => const OnboardingScreen(),
              '/giftChoose': (context) => const GiftChoose(),
            },
            home:
                hasSeenOnboarding ? const HomePage() : const OnboardingScreen(),
          );
        }
        );
  }
}

Future<void> setLocale(String languageCode) async {
  final SharedPreferences preferences = await SharedPreferences.getInstance();
  preferences.setString('languageCode', languageCode);
}

Future<String?> getLocale() async {
  WidgetsFlutterBinding.ensureInitialized();
  final SharedPreferences preferences = await SharedPreferences.getInstance();
  return preferences.getString('languageCode');
}

class LocaleModel extends ChangeNotifier {
  Locale? _locale;

  Locale? get locale => _locale;

  void set(Locale locale) {
    _locale = locale;
    notifyListeners();
  }
}