Getting error while login in quickblox

I have an application in that i have use the quickblox for imaplementing chat but while logging to quickblox by using below code i am getting the error Something wrong with your Account Key or check it at http://admin.quickblox.com/account or set your endpoints for QuickBlox API manually please help me to solve this error. Many thanks in advance.

NSString *userName = self.txtUserField.text;
NSString *password = self.txtUserField.text;

QBSessionParameters *parameters = [QBSessionParameters new];
parameters.userLogin = userName;
parameters.userPassword = password;
parameters.userEmail = @"a@a.com";

[QBRequest createSessionWithExtendedParameters:parameters successBlock:^(QBResponse *response, QBASession *session) {

    QBUUser *user = [QBUUser user];
    user.ID = session.userID;
    user.password = password;
    // set Chat delegate
    [QBChat instance].delegate = self;
    // login to Chat
    [[QBChat instance] loginWithUser:user];
} errorBlock:^(QBResponse *response) {

     NSLog(@"error: %@", response.error);

}];