Opening Instagram app on button click

Hello Guys am trying to open instagram app on button click but not able to open
here s what i did

NSString *instagramURL = @"instagram://app";
NSURL *ourURL = [NSURL URLWithString:instagramURL];
if ([[UIApplication sharedApplication]canOpenURL:ourURL])
    [[UIApplication sharedApplication]openURL:ourURL];        
} else {
    //The App is not installed. It must be installed from iTunes code.
    NSString *iTunesLink = @"//Your itunes Url";
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:iTunesLink]];
    UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"URL error"
                                                   message:[NSString stringWithFormat:
                                                       @"No custom URL defined for %@", ourURL]
                                                  delegate:self cancelButtonTitle:@"Ok"
    [alert show];

and i set urlschema in plist as instagram

where am doing wrong and i did write any line in app delegate

-(BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<NSString *,id> *)options{
    return YES;

and i registered app in instagram also am new to ios any help would be appriciated