How hook the multitask on iOS 12

Question

Hi, I'm create a tweak tu custom multitask on iOS but don't find the good header.

My code :

%hook SBMainSwitcherViewController

-(void)viewDidLoad {
%orig;
UIAlertController * alert=[UIAlertController 

alertControllerWithTitle:@"AppSwitcher" message:@"Clear cache"preferredStyle:UIAlertControllerStyleAlert];

   UIAlertAction* yesButton = [UIAlertAction
                        actionWithTitle:@"Thank God !"
                        style:UIAlertActionStyleDefault
                        handler:^(UIAlertAction * action)
                        {
                        }];
   [alert addAction:yesButton];
   [self presentViewController:alert animated:YES completion:nil];
}

%end

It's doesn't work...

I just want at this time to show a UIAlert when multitask is activate.

Thx for help