How can I make my app detect bluetooth device?

I'm making a app that plays sounds when the buttons are tapped. But when using this app with bluetooth headphones or airpods, the users will experience a slight delay when they tap the buttons. And I want the app to give the users an alert when it detects bluetooth devices like airpods and tell them that they might notice a delay when using bluetooth headphones or airpods. I know how to set up an alert using UIAlertController. But I don't know how to let my app detect bluetooth devices. Could you give me some directions regarding how to trigger the alert when users use bluetooth devices?