Need help with code for my plugin.

Hi i write plugin to drop items from stone and I have a problem because I not get drop
This is the code:

PHP:

<?php

namespace DawixQMC\drop;

use pocketmine\plugin\PluginBase;
use pocketmine\event\Listener;
use pocketmine\utils\TextFormat;
use pocketmine\event\block\BlockBreakEvent;
use pocketmine\block\Block;
use pocketmine\item\Item;

class Main extends PluginBase implements Listener{
  
    public function onEnable(){
      $this->getServer()->getPluginManager()->registerEvents($this,$this);
      $this->getServer()->getLogger()->info(TextFormat::GREEN."[PocketDrop] Activated!");
    }
  
    public function blockBreak(BlockBreakEvent $event){
                  
                    $block = $event->getBlock();
                    $player = $event->getPlayer();
                    $id = $block->getId();
                  
                    if($id === Block::STONE){
                        switch(mt_rand(1, 200)){
                      
                case 1:
                        $player->getLevel()->setBlock($block, new Block(Block::AIR));
                        $player->getLevel()->dropItem($block, new Item(264, 0, 1));
                        $player->sendMessage("PocketMC Diamond!");
                        break;
                        }
                        }
    }
}

Any player edit this code for me or check what is wrong?

do you know how it works? it randomly happens.

Yes I know that random but dug a lot of cobble and nothing could

first, Level::dropItem($i) requires an item object...

I do not know English well
You can explain to me what I have to add improved?