Do I have to attribute listeners to this class implements (again Minecraft xD)?

Because of the

public void onPlayerUse (PlayerInteractEvent e) {

Because in the main class is yes to register

pm.registerEvents (new ItemInHand_DragonEgg_Fly (), this);

Because of the "Event" I ask stop🤔

And yes, the name of the class is long, but who cares

Yes, most of the time you either have a CommandExecutor or Listener.

As soon as you have any event, in most cases "listener" is to be implemented.

Yes you have to register the class in which your event should be your onPlayerUse

Which is wrong by the way because the player is not used but uses something

In your long already registered class you do not need to do anything

Of course

onPlayerUse (PlayerInteractEvent e)

And that's not how I understand your grammar…