How to add a command from another plugin to my plugin?

I have 2 questions
How to add a command from another plugin to my plugin?

And
If you click on the item in your menu that it uses a bungee command

(My english is not good)

 

Thanks, but i don't understand the first one

 

Thanks! But now where do it need to put the first one?

Code (Text):

package inventory;

import org.bukkit.ChatColor;
import org.bukkit.Effect;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;

public class InventoryClick implements Listener {
 
    @EventHandler
    public void onInventoryClick(InventoryClickEvent event) {
        Inventory inv = event.getInventory();
        if(!(inv.getTitle().equals("Server Travel")))
            return;
     
            if(!(event.getWhoClicked() instanceof Player))
            return;
     
        Player player =(Player) event.getWhoClicked();  
        ItemStack item = event.getCurrentItem();
        event.setCancelled(true);
     
        if(item.getType() == Material.GOLD_BLOCK) {
            player.teleport(player.getWorld().getSpawnLocation());
            player.sendMessage(ChatColor.GREEN + "Teleported to hub!");
         
            event.setCancelled(true);
            player.closeInventory();
         
            player.getWorld().playEffect(player.getLocation(), Effect.BLAZE_SHOOT, 1);
         
}
    }
}

And the teleport thing is gonna be removed and the bungee thing is gonna be added

 

Sorry, but I meant the second and i have this now (I'm very noob)

Code (Text):

package inventory;

import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;

public class InventoryClick implements Listener {
   
    @EventHandler
    public void onInventoryClick(InventoryClickEvent event) {
        Inventory inv = event.getInventory();
        if(!(inv.getTitle().equals("Server Travel")))
            return;
       
            if(!(event.getWhoClicked() instanceof Player))
            return;
       
        Player player =(Player) event.getWhoClicked();  
        ItemStack item = event.getCurrentItem();
        event.setCancelled(true);
   
    }
       
        @EventHandler
        public void onPlayerInteract(PlayerInteractEvent e) {
           
            Player player = e.getPlayer();
           
            {
            }

            event.setCancelled(true);
            player.closeInventory();
       
           
            {
    }
        }
}

I get an error with this event.setCancelled(true); the last one and where do i need to put the bungee command? I don't understand xd

 

the error is: Syntax error

 

i tried to fix it but it messed up and now there is a red line under event

 

i dont understand you xD