Subscribe to an audience with Parse Dashboard

Question

I'm having trouble subscribing to an audience from my iOS app for Push Notifications. I've created several Audiences from the dashboard on Back4App. But I don't know how to subscribe or unsubscribe from my app in Xcode.

My problem is that whether they're subscribed or not; the device is always getting the notification

This is how I'm subscribing:

PFInstallation *currentInstallation = [PFInstallation currentInstallation];

[currentInstallation addUniqueObject:@"General" forKey:@"channels"];
[currentInstallation addUniqueObject:@"Events" forKey:@"channels"];

[currentInstallation saveInBackground];

And unsubscribing:

[currentInstallation removeObject:announcementTitles[indexPath.row] forKey:@"channels"];

But whichever way, when I send a notification to a specific audience from the dashboard, it sends to everyone.

Thanks