Wrong

What's wrong
This code it's doesn't work

PHP:

    public function Item(PlayerItemHeldEvent $event){
        $player = $event->getPlayer();      
        $it = $event->getItem()->getID();      
        if($it == 288){      
            $player->setNameTag("§b§lLegend§cPvP §7| §r§e".$player->getName());
        }
    }

You've only have 2 closing }

Sorry, misread.

Try getId() instead of getID().
Also, try === since they are of the same type.

This ?

PHP:

public function Item(PlayerItemHeldEvent $event){
        $player = $event->getPlayer();      
        $it = $event->getItem()->getID();      
        if($it == getId()->288){      
            $player->setNameTag("§b§lLegend§cPvP §7| §r§e".$player->getName());
        }
    }

What @HotFireyDeath meant is

PHP:

public function Item(PlayerItemHeldEvent $event){
    $player = $event->getPlayer();
    $it = $event->getItem()->getId(); //here
    if($it === 288){ //here
        $player->setNameTag("§b§lLegend§cPvP §7| §r§e".$player->getName());
    }
}


Thanks i love you !

Instead of 288 you should use Item::THE_ITEM_YOU_WANT

That's the same.. Item::ITEMHERE returns the ID.

What if the ID's will change in future? Will you change all ID's in all your plugins? Instead of using a static one use this method.
@PEMapModder

Ugh, misread it. I somehow thought you mean change Item::ITEM to the ID..