마크 페이퍼 1.21로 커맨드 입력하면 채팅에 뭐 뜨게 해놨는데 작동이 안됩니다

package mteword.mteworld;

import org.bukkit.plugin.java.JavaPlugin;

public final class main extends JavaPlugin {

    @Override
    public void onEnable() {
        // Plugin startup logic
        getLogger().info("플러그인 활성화");
        if (getCommand("aaa") != null) {
            getCommand("aaa").setExecutor(new command());
        }
    }

    @Override
    public void onDisable() {
        // Plugin shutdown logic
    }
}

package mteword.mteworld;

import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.jetbrains.annotations.NotNull;

public class command implements CommandExecutor {
    @Override
    public boolean onCommand(@NotNull CommandSender commandSender, @NotNull Command command, @NotNull String s, @NotNull String[] strings) {
        if (commandSender instanceof Player) {
            Player p = (Player) commandSender;
            p.sendMessage("테스트");
            return true;
        } else {
            commandSender.sendMessage("이 명령어는 플레이어만 사용할 수 있습니다.");
            return true;
        }
    }
}

main: mteword.mteworld.Main
version: 1.0
name: "MTEWORLD"
api-version: 1.21
commands:
  aaa:
    description: test
    usage: /<command>

어디가 문제인가여

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