Error: Call to undefined method

Hello
Guys this code error and not work. what should i do?

PHP:

<?php

namespace Legoboy\ST;

use pocketmine\plugin\PluginBase;
use pocketmine\utils\Config;

class Loader extends PluginBase{
    
    public static $db;
    
    public function onLoad(){
        if(!file_exists($this->getDataFolder())){
            @mkdir($this->getDataFolder());
        }
        $this->saveDefaultConfig();
        $mysql = self::$db = new \mysqli(!is_null($this->getConfig()->get("server-name")) ? $this->getConfig()->get("server-name") : "localhost", $this->getConfig()->get("username"), $this->getConfig()->get("password"), $this->getConfig()->get("simpleauth-dbname"), !is_null($this->getConfig()->get("port")) ? ((int)$this->getConfig()->get("port")) : 3306);
        if($mysql->connect_error){
            die("Connection failed: " . $mysql->connect_error);
            $this->getServer()->getPluginManager()->disablePlugin($this);
            return;
        }
        $resource = $this->getResource("mysql.sql");
        $mysql->query(stream_get_contents($resource));
        fclose($resource);
    }
    
    public function onEnable(){
        $this->process();
    }
    
    public static function getMySQL(){
        return self::$db;
    }
    
    public function process(){
        $path = $this->getScheduler()->getPluginManager()->getPlugin("SimpleAuth")->getDataFolder() . "/players/";
        $this->getScheduler()->scheduleAsyncTask(new QueryTask($path));
    }
}


PHP:

<?php

namespace Legoboy\ST;

use pocketmine\Server;
use pocketmine\scheduler\AsyncTask;

use Legoboy\ST\Loader as ST;

class QueryTask extends AsyncTask{
    
    private $path;
    
    const KEY_MYSQL = 'st.mysql';
    const USERS = 0;
    
    public function __construct($path){
        $this->path = $path;
    }

    public function onRun(){
        foreach(glob($this->path . "*/*.yml") as $file){
            $data = yaml_parse_file($file);
            var_dump($data);
            $player = strtolower(basename($file, ".yml"));
            $regdate = $data['registerdate'];
            $logindate = $data['logindate'];
            $ip = $data["lastip"];
            $password = $data['hash'];
            $result = $this->getConnection()->query("INSERT INTO simpleauth_players (name, hash, registerdate, logindate, lastip)
                                        VALUES ('$pname', '$hash', '$regdate', '$logindate', '$ip')");
            if($result){
                self::USERS++;
            }else{
                $this->getLogger()->critical("Unable to sumbit user to MySQL Database: Query error.");
                continue;
            }
        }
    }

    public function onCompletion(Server $server){
        $base = $server->getPluginManager()->getPlugin("SimpleTransfer");
        if($base instanceof PluginBase){
            $base->getLogger()->warning("All users SUCCESSFULLY queried into database.");
        }
    }
    
    //PEMapModder's code
    
    /**
     * @return \mysqli
     */
    
    public function getConnection(){
        $mysql = $this->getFromThreadStore(sef::KEY_MYSQL);
        if(!($mysql instanceof \mysqli)){
            $mysql = ST::getMySQL();
            $this->saveToThreadStore(self::KEY_MYSQL, $mysql);
        }
        return $mysql;
    }
    
    public function saveToThreadStore($identifier, $value){
        global $store;
        if(!$this->isGarbage()){
            $store[$identifier] = $value;
        }
    }
    
    public function getFromThreadStore($identifier){
        global $store;
        return $this->isGarbage() ? null : $store[$identifier];
    }
}

and console send me this error:

Code:

[01:25:02] [Server thread/INFO]: Enabling SimpleTransfer v1.0.0
[01:25:02] [Server thread/CRITICAL]: Error: "Call to undefined method pocketmine\scheduler\TaskScheduler::getPluginManager()" (EXCEPTION) in "plugins/DataTransfer-master/src/Legoboy/ST/Loader" at line 37
[01:25:02] [Server thread/DEBUG]: #0 plugins/DataTransfer-master/src/Legoboy/ST/Loader(29): Legoboy\ST\Loader->process()
[01:25:02] [Server thread/DEBUG]: #1 src/pocketmine/plugin/PluginBase(123): Legoboy\ST\Loader->onEnable()
[01:25:02] [Server thread/DEBUG]: #2 src/pocketmine/plugin/PluginManager(580): pocketmine\plugin\PluginBase->setEnabled(boolean 1)
[01:25:02] [Server thread/DEBUG]: #3 src/pocketmine/Server(2002): pocketmine\plugin\PluginManager->enablePlugin(object Legoboy\ST\Loader)
[01:25:02] [Server thread/DEBUG]: #4 src/pocketmine/Server(1988): pocketmine\Server->enablePlugin(object Legoboy\ST\Loader)
[01:25:02] [Server thread/DEBUG]: #5 src/pocketmine/Server(1782): pocketmine\Server->enablePlugins(integer 1)
[01:25:02] [Server thread/DEBUG]: #6 src/pocketmine/PocketMine(275): pocketmine\Server->__construct(object BaseClassLoader, object pocketmine\utils\MainLogger, string[52] C:\Users\Administrator\Desktop\test server\LegendMc\, string[60] C:\Users\Administrator\Desktop\test server\LegendMc\plugins\)
[01:25:02] [Server thread/DEBUG]: #7 src/pocketmine/PocketMine(299): pocketmine\server()
[01:25:02] [Server thread/DEBUG]: #8 (1): require(string[107] phar://C:/Users/Administrator/Desktop/test server/LegendMc/PocketMine-MP.phar/sr)
[01:25:02] [Server thread/INFO]: Disabling SimpleTransfer v1.0.0

 

getPluginManager() can only be called using a server instance. you are trying to use a task instance.

error message says line 37 of Loader.php. Please read.

 

tnx for help but i dont know what i should do? can you say to me what should i do? wich code should with replace with another?

 

line 37
getPluginManager() is called from $this
getPluginManager() cannot be called from $this
call the function from the plugin base instead