Help for task

This is my code :

PHP:

<?php

namespace moch\pl;

 use pocketmine\plugin\PluginBase;
 use pocketmine\Player;
 use pocketmine\Server;
 use pocketmine\event\Listener;
 use pocketmine\event\player\PlayerJoinEvent;
 
 use pocketmine\item\Item;
 use pocketmine\event\block\BlockPlaceEvent;
 use pocketmine\event\block\BlockBreakEvent;
 
 use pocketmine\block\Block;
 
 use pocketmine\utils\Config;
 use pocketmine\math\Vector3;
 
 use pocketmine\level\particle\{DustParticle, FlameParticle, FloatingTextParticle, EntityFlameParticle, CriticalParticle, ExplodeParticle, HeartParticle, LavaParticle, MobSpawnParticle, SplashParticle};
 
class Main extends PluginBase implements Listener {
    
    public $plugin;

    public function onEnable(){
        $this->getLogger()->info("Leaderboard Enable...");
        
        @mkdir($this->getDataFolder() . "Top_Player");
        
        $this->getServer()->getPluginManager()->registerEvents($this, $this);
    }
    
    public function LeadTask(PlayerJoinEvent $event){
        $player = $event->getPlayer();
        
        $this->getScheduler()->scheduleDelayedTask(new LeadTask($this, $player), 20); //30min.
    }
    
    public function setfarmdata(BlockBreakEvent $event) {
        $player = $event->getPlayer();
        $name = $player->getName();
        $break = $event->getBlock();
        if($break->getId() === 141 || $break->getId() === 142 || $break->getId() === 59 || $break->getId() === 86 || $break->getId() === 103){
            $data = new Config($this->getDataFolder() . "Top_Player/topfarm.yml", Config::YAML);
            $up = $data->get($name);
            $data->set($name, $up + 0.1);
            $data->save();
        }
    }
    
    public function createtopten(PlayerJoinEvent $event){
        $player = $event->getPlayer();
        $w = $this->getConfig()->get("world");
        $world = $player->getLevel()->getName() === "$w";
        $top = $this->getConfig()->get("enable");
        
        if($world){
            if($top == "true"){
                $this->TopFarm($player);
            }
        }
    }
    
    public function TopFarm($p){
        $player = $p->getPlayer();
        $data = new Config($this->getDataFolder() . "Top_Player/topfarm.yml", Config::YAML);
        $swallet = $data->getAll();
        $c = count($swallet);
        $message = "";
        $top = "§b§l=====§eTopFarm§b§l=====";
        arsort($swallet);
        $i = 1;
        foreach ($swallet as $name => $amount) {
                    
            $message .= "§b ".$i.". §7".$name."  §akeep  §f".$amount." §aItem\n";
            if($i > 9){
                break;
            }
            ++$i;
        }
        
        $x = $this->getConfig()->get("farm-x");
        $y = $this->getConfig()->get("farm-y");
        $z = $this->getConfig()->get("farm-x");
        
        $p = new FloatingTextParticle(new Vector3($x, $y + 1, $z), $message, $top);
        $player->getLevel()->addParticle($p);
    }
}
    

 

First of all

It's not 30 minute but 1 second .-.
Than were is the task class located?? The error is pretty clear