The error am getting while trying to sign in using email while 2FA has already been regustered is please complete a second factor challenge to finish signing into the account.

  Future<void> _signIn() async {
    if (!_formKey.currentState!.validate()) return;

    setState(() => _isLoading = true);

    try {
      final userCredential = await _auth.signInWithEmailAndPassword(
        email: _emailController.text.trim(),
        password: _passwordController.text.trim(),
      );

      if (!mounted) return;

      if (userCredential.user != null) {
        context.go('/');
        showToast("Welcome Back 👋");
      } else {
        showToast("Failed to sign in. Please try again.");
      }
    } on FirebaseAuthMultiFactorException catch (e) {
      if (kDebugMode) print(e);
      await _handleMultiFactorException(e);
    } on FirebaseAuthException catch (e) {
      if (kDebugMode) print(e);
      showToast(e.message ?? "Authentication failed");
    } finally {
      if (mounted) setState(() => _isLoading = false);
    }
  }

  Future<void> _handleMultiFactorException(
      FirebaseAuthMultiFactorException e) async {
    final resolver = e.resolver;
  

    if (resolver.hints.isNotEmpty) {
      if (resolver.hints.first is PhoneMultiFactorInfo) {
        await _handlePhoneMultiFactor(resolver);
      } else {
        showToast("Unsupported second factor authentication method.");
      }
    } else {
      showToast("No second factor challenge available.");
    }
  }

  Future<void> _handlePhoneMultiFactor(MultiFactorResolver resolver) async {
    final phoneHint = resolver.hints.first as PhoneMultiFactorInfo;

    try {
      final verificationId =
          await _startPhoneVerification(phoneHint, resolver.session);
      final smsCode = await _promptForSMSCode();

      if (smsCode != null) {
        final credential = PhoneAuthProvider.credential(
          verificationId: verificationId,
          smsCode: smsCode,
        );
        await _finishSignIn(resolver, credential);
      } else {
        showToast("SMS code is required to complete sign-in.");
      }
    } catch (e) {
      showToast("Error during phone verification: $e");
    }
  }

  Future<String> _startPhoneVerification(
      PhoneMultiFactorInfo hint, MultiFactorSession session) async {
    Completer<String> verificationIdCompleter = Completer<String>();

    await FirebaseAuth.instance.verifyPhoneNumber(
      multiFactorSession: session,
      phoneNumber: hint.phoneNumber,
      verificationCompleted: (PhoneAuthCredential credential) {
        // Auto-retrieval is not supported for MFA
      },
      verificationFailed: (FirebaseAuthException e) {
        showToast("Failed to verify phone number: ${e.message}");
        verificationIdCompleter.completeError(e);
      },
      codeSent: (String verificationId, int? resendToken) {
        verificationIdCompleter.complete(verificationId);
      },
      codeAutoRetrievalTimeout: (String verificationId) {
        showToast('Code retrieval timed out. Please enter the code manually.');
      },
    );

    return verificationIdCompleter.future;
  }

  Future<void> _finishSignIn(
      MultiFactorResolver resolver, PhoneAuthCredential credential) async {
    try {
      final multiFactorAssertion =
          PhoneMultiFactorGenerator.getAssertion(credential);
      final userCredential = await resolver.resolveSignIn(multiFactorAssertion);

      if (userCredential.user != null) {
        if (!mounted) return;
        context.go('/');
        showToast("Welcome Back 👋");
      } else {
        showToast("Failed to complete multi-factor authentication.");
      }
    } catch (e) {
      showToast("Error during multi-factor sign-in: $e");
    }
  }

  Future<String?> _promptForSMSCode() async {
    final TextEditingController smsController = TextEditingController();

    return showDialog<String>(
      context: context,
      barrierDismissible: false,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Enter SMS Code'),
          content: TextField(
            controller: smsController,
            keyboardType: TextInputType.number,
            maxLength: 6,
            decoration: const InputDecoration(hintText: '000000'),
          ),
          actions: <Widget>[
            TextButton(


              child: const Text('Cancel'),
              onPressed: () => Navigator.of(context).pop(),
            ),
            TextButton(
              child: const Text('Submit'),
              onPressed: () =>
                  Navigator.of(context).pop(smsController.text.trim()),
            ),
          ],
        );
      },
    );
  }

enter image description here While logging in this is the error i am getting. PLEASE HELP.for front end its flutter and for the backend its firebase