how to send data from server in objective c

webService.m

-(void)sendData:(NSString*)email : (NSString*)password :(NSString*)user_id : (NSString*)urlString : (NSString*)name {
    
    NSLog(@"sendData");
    
    NSURL *url = [NSURL URLWithString:urlString];
    NSMutableURLRequest * urlRequest = [NSMutableURLRequest requestWithURL:url];
    
    NSString *dataString = [NSString stringWithFormat:@"email=%@&password=%@&id=%@",email,password,user_id];
    
    NSData *requestData = [dataString dataUsingEncoding:NSUTF8StringEncoding];
    NSLog(@"requestData%@",requestData);
    [urlRequest setHTTPMethod:@"POST"];
    [urlRequest setValue:@"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" forHTTPHeaderField:@"Accept"];
    [urlRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [urlRequest setHTTPBody: requestData];
    NSURLSessionDataTask * dataTask = [[NSURLSession sharedSession] dataTaskWithRequest:urlRequest completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        NSLog(@"data=%@",data);
        if (data.length>0 && error==nil) {
            @try {
               
                NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:0 error:NULL];
                NSLog(@"Dict=%@",dict);
                NSString *ss = [NSString stringWithFormat:@"%@",[dict valueForKey:@"result"]];
                NSLog(@"ss %@",ss);
                if([ss isEqualToString:@"success"]){
                    
                    NSLog(@"success");
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [[NSUserDefaults standardUserDefaults]setValue:@"name" forKey:@"name"];
                        
                        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
                        UITabBarController*vc = [storyboard instantiateViewControllerWithIdentifier: @"MyTabBarController"];
                        self.navigationItem.hidesBackButton = YES;
                        self.navigationItem.backBarButtonItem = nil;
                        [[self navigationController]pushViewController:vc animated:YES];
                    });
                    
                }else{
                    
                    dispatch_async(dispatch_get_main_queue(), ^{
                        UIAlertController * alert = [UIAlertController
                                                     alertControllerWithTitle:@"Invalid"
                                                     message:@"Invalid email or passwor.try Again!"
                                                     preferredStyle:UIAlertControllerStyleAlert];
                        
                        UIAlertAction* fbButton = [UIAlertAction
                                                   actionWithTitle:@"Retry"
                                                   style:UIAlertActionStyleDefault
                                                   handler:^(UIAlertAction * action)
                                                   {
                                                       // Add your code
                                                       
                                                       
                                                   }];
                        [alert addAction:fbButton];
                        [self presentViewController:alert animated:YES completion:nil];
                    });
                    
                    
                }
                
            } @catch (NSException *exception) {
                NSLog(@"Exception %@",exception.description);
            } @finally {
                
            }
            
        }
        
    }];
    
    [dataTask resume];
}