Plugin crash

My Plugin crash when i join on my server with this error:
“Call to a undefined method pocketmine\Server::getDeafaultSpawn()“ (EXCEPTION)
Here is my Code

PHP:

<?php

namespace Main;

use pocketmine\plugin\PluginBase;
use pocketmine\utils\TextFormat as Color;
use pocketmine\item\Item;
use pocketmine\block\Block;
use pocketmine\Player;
use pocketmine\event\Listener;
use pocketmine\event\player\PlayerJoinEvent;
use pocketmine\event\player\PlayerQuitEvent;
use pocketmine\event\player\PlayerRespawnEvent;
use pocketmine\event\player\PlayerDeathEvent;
use pocketmine\event\entity\EntityDamageEvent;
use pocketmine\event\entity\EntityDamageByEntityEvent;
use pocketmine\entity\Effect;
use pocketmine\event\block\BlockBreakEvent;
use pocketmine\level\Level;
use pocketmine\math\Vector3;
use pocketmine\event\player\PlayerInteractEvent as PIE;
use pocketmine\item\enchantment\Enchantment;
use pocketmine\command\Command;
use pocketmine\command\CommandSender;
use pocketmine\Server;

class SoupFFA extends PluginBase implements Listener {
   
    public $prefix = Color::AQUA. "Soup". Color::RED . "FFA" . Color::GRAY . " |";
   
    public function onEnable() {
       
        $this->getServer()->getPluginManager()->registerEvents($this, $this);
        $this->getLogger()->info($this->prefix . Color::GREEN . " wurde Aktiviert!");
        $this->getLogger()->info($this->prefix . "Made By " . Color::GOLD . " Jonas!");
       
    }
   
    public function onJoin(PlayerJoinEvent $event) {
       
        $player = $event->getPlayer();
        $player->teleport($this->getServer()->getDefaultSpawn()->getSaveSpawn());

Thats not all. The Error is in the last line from my Code.

 

It is getDefaultLevel() and getSafeSpawn()

 

Thanks its work