[CSAppRate sharedInstance].appID = @"YOURAPPID";
Second you must set the property of scene which is a enum named CSRateScene, in this enum there's 2 types, CSRateInApp means rating in your app, CSRateInStore means rating your app by turning into Apple App Store.
[CSAppRate sharedInstance].scene = CSRateInApp;
[CSAppRate setRaterAppID:@"YOURAPPID" scene:CSRateInApp];
CSAppRate *instance = [CSAppRate sharedInstance];
instance.title = @"Notice";
instance.message = @"Enjoy the App? Please rate it!";
instance.rate = @"Rate now";
instance.cancel = @"Next time";
[CSAppRate showRatingAlertIn:viewController];
[CSAppRate goToRateTheAppIn:viewController];