Flutter – Error on authentication Ios/IPHONE on firebase

I has published an app on Apple store et was. surprised that authentication by phone number caused an error on Ios/IPHONE devices.

My Application is developper with flutter .
Authentication works fine for Android devices.
Also when using phone number of an Iphone device on an Android device, tha Iphone receive well the OTP.

When authentication is made by Iphone, an error occured (Firebase)

10.18.0 – [FirebaseAuth][I-AUT000018] Error getting App Check token; using placeholder token instead. Error: Error Domain=com.google.app_check_core Code=0 "The server responded with an error:

• URL: https://firebaseappcheck.googleapis.com/v1/projects/myProject-application/apps/1:XXXXXXXXXXXX:ios:XXXXXXXXXXXXXXXXXXXXXX:exchangeDeviceCheckToken
  ”’ – HTTP status code: 403
• Response body: {
  "error": {
  "code": 403,
  "message": "App attestation failed.",
  "status": "PERMISSION_DENIED"
  }
  }
  ”’
  UserInfo={NSLocalizedFailureReason=The server responded with an error:

All configuration is done on Firebase console and Apple developper account (certificates, keys …)

I have read many suggested solutions on the web, but no luck.
Can someone help please.

Thanks in advance.

ADDED MY CODE :

_verifyPhoneButton(String phone) async {
final auth = FirebaseAuth.instance;

await firebaseAuth.verifyPhoneNumber(
    phoneNumber: phone,
    timeout: const Duration(seconds: 120),

    verificationCompleted: (AuthCredential  phoneAuthCredential) async {
      firebaseAuth.signInWithCredential(auth as AuthCredential)
          .then((result) =>{
        if(result != null && result.user != null){
          print("Authentication is Successful")
        }else{
          print("Authentication failed!")
        }
      }).catchError((error){
        print("Authentication failed!");
      });
    },
    verificationFailed: (verificationFailed) async {
      await showDialog(
          context: context,
          barrierDismissible: false,
          builder: (BuildContext context) => CupertinoAlertDialog(
                title: Text("Erreur: ${AppLocalizations.of(this.context)!.inscription}", style: styles.labelTextBoldColor(context, 18)),
                content: Text(verificationFailed.message!, style: styles.labelTextColor(context, 13)),
                actions: <Widget>[
                  CupertinoDialogAction(
                    child: Text(
                      AppLocalizations.of(this.context)!.compris,
                      style: styles.labelTextColor(context, 13),
                    ),
                    onPressed: () {
                      Navigator.of(context).pop();
                    },
                  ),
                ],
              ));
    },
    codeSent: (verificationId, resendingToken) async {
      verificationIDFromFirebase = verificationId;
      //print("TIME OUT $verificationId");
    },
    codeAutoRetrievalTimeout: (verificationId) async {
      //print("TIME OUT");
    });

}