Obtener estado de entrega de voz con Objective C / iPhone

NSString *aclass = @"voice";
NSString *method = @"getdeliverystatus";
NSString *user = @"user";
NSString *password = @"password";
NSString *messages = @"123456,123457,123458";
NSString *output = @"";
NSString *targetUrl = [NSString stringWithFormat:@"https://www.afilnet.com/api/http/?class=%@&method=%@&user=%@&password=%@&messages=%@&output=%@", aclass, method, user, password, messages, output]
	
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setHTTPMethod:@"GET"];
[request setURL:[NSURL URLWithString:targetUrl]];

[[[NSURLSession sharedSession] dataTaskWithRequest:request completionHandler:
	^(NSData * _Nullable data,NSURLResponse * _Nullable response,NSError * _Nullable error) {
		NSString *myString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
		NSLog(@"Data received: %@", myString);
}] resume];