I need to execute a command when a player logs into the server on his behalf. And it is important that this is a server and not a single player game
 
	 
 
package com.homanti.autologin;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.util.text.StringTextComponent;
import net.minecraftforge.event.entity.player.PlayerEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.Mod.EventBusSubscriber;
import net.minecraftforge.fml.common.Mod.EventBusSubscriber.Bus;
@Mod("autologin")
@EventBusSubscriber(bus = Bus.FORGE)
public class AutoLogin {
    @SubscribeEvent
    public static void onPlayerLogin (PlayerEvent.PlayerLoggedInEvent event) {
        PlayerEntity player = event.getPlayer();
        /// write a command on behalf of the player "/login"
    }
}