UI not showing

PHP:

<?php

namespace Aenteritas;

use pocketmine\Server;
use pocketmine\Player;
use pocketmine\event\Listener;
use pocketmine\plugin\PluginBase;
use pocketmine\command\Command;
use pocketmine\command\CommandSender;
use pocketmine\utils\Config;
use pocketmine\event\player\PlayerExhaustEvent;
use pocketmine\event\player\PlayerChatEvent;
use pocketmine\event\player\PlayerJoinEvent;
use pocketmine\event\Cancellable;

class Main extends PluginBase implements Listener {
   
    public function onEnable(){
     $this->getServer()->getPluginManager()->registerEvents($this, $this);
        $this->getLogger()->info("aktiviert!");
    }
   
    public function onJoin(PlayerJoinEvent $event){
        $player = $event->getPlayer();
       
        $event->setJoinMessage(null);
        $this->openMyForm($player);
    }
   
    public function openMyForm($player){
        $api = $this->getServer()->getPluginManager()->getPlugin("FormAPI");
        $form = $api->createSimpleForm(function (Player $player, int $data = null){
            $result = $data;
            if($result === null){
                return true;
            }
            switch($result){
                case 0:
                    $player->sendMessage("§7[§eLord§bTown§7] §4Wir können dich nicht teleportieren, da der Server §7(§eCityBuild§7) §4offline ist! (Error-38273)");
                break;
               
                case 1:
                    $player->sendMessage("§7[§eLord§bTown§7] §4Wir können dich nicht teleportieren, da der Server §7(§bTNTRun§7) §4 offline ist! (Error-38279)");
                break;
            }
           
        });
       
        $form->setTitle("§l§eNavigator");
        $form->setContent("Willkommen auf §eLord§bTown§r! Bitte wähle nun aus, was Du Spielen willst!");
        $form->addButton("§eCityBuild §7[§2ONLINE§7]");
        $form->addButton("§bTNTRun §7[§4OFFLINE§7]");
        $form->sendToPlayer($player);
        return $form;
    }
   
}

?>


When i join the server, nothing happens (no UI is showing and no output in console).

What is wrong?
I also have FormAPI installed.

 

What output should you have in the console? One thing I noticed is

PHP:

  $form = $api->createSimpleForm(function (Player $player, int $data = null){ 

only has a single closing ), with 2 opening (, which should throw a syntax error.

 

Because there is a PlayerJoinEvent bug exist. You need to send your form with delay