// Initialize the activity indicator view
CGRect frame = CGRectMake(40, 40, 40, 40);
FLLActivityIndicatorView *activityIndicatorView = [[FLLActivityIndicatorView alloc] initWithFrame:frame];

// Set the line width of the activity indicator view
activityIndicatorView.lineWidth = 4;

// Set the stroke color of the activity indicator view
activityIndicatorView.strokeColor = [UIColor redColor];

// Add it as a subview
[self.view addSubview:activityIndicatorView];

...

// Start animation
[activityIndicatorView startAnimating];

...

// Stop animation
[activityIndicatorView stopAnimating];

// Create the NSURLSessionConfiguration and then create a session with that configuration.
NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration];

// Create the NSURLRequest using either an NSURL
NSURL *url = [NSURL URLWithString:@"https://httpbin.org/get"];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];

// Initialize the shared instance activity indicator controller.
FLLActivityIndicatorController *activityIndicatorController = [FLLActivityIndicatorController activityIndicatorController];

// Show the activity indicator
[activityIndicatorController show];

// Call the web service
NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request
                                            completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
                                                // Hide the activity indicator
                                                [activityIndicatorController hide];
                                            }];
[dataTask resume];