Cognito验证电子邮件/登录手机

Question

登录时通过电子邮件验证（如果用户未在注册期间进行验证）。目标-c 认知

这没有给我任何回应。 我没有使用密码验证或 MFA 。谁能帮我得到答复。

-(void)verifyUser{
    {

        AppDelegate *delegate = (AppDelegate*)[[UIApplication sharedApplication] delegate];
                self.user = [delegate.pool getUser :@"rahuld@tweebr.com"];

        [[_user getAttributeVerificationCode:@"rahuld@tweebr.com"] continueWithSuccessBlock:^id _Nullable(AWSTask<AWSCognitoIdentityUserGetAttributeVerificationCodeResponse *> * _Nonnull task) {
            dispatch_async(dispatch_get_main_queue(), ^{
                if(task.error){

                    UIAlertController * alert = [UIAlertController
                                                 alertControllerWithTitle:nil
                                                 message:task.error.userInfo[@"message"]                                             preferredStyle:UIAlertControllerStyleAlert];
                    UIAlertAction* errorButton = [UIAlertAction
                                                  actionWithTitle:@"Ok"
                                                  style:UIAlertActionStyleDefault
                                                  handler:^(UIAlertAction * action) {
                                                  }];

                    [alert addAction:errorButton];
                    [self presentViewController:alert animated:YES completion:nil];


                }else {
                    UIAlertController * alert = [UIAlertController
                                                 alertControllerWithTitle:nil
                                                 message:@"Otp has been sent to your mobile/Email"                                             preferredStyle:UIAlertControllerStyleAlert];
                    UIAlertAction* successButton = [UIAlertAction
                                                    actionWithTitle:@"Ok"
                                                    style:UIAlertActionStyleDefault
                                                    handler:^(UIAlertAction * action) {


                                                    }];

                    [alert addAction:successButton];
                    [self presentViewController:alert animated:YES completion:nil];
                }
            });
            return nil;
        }];
    }
}

我没有回应。