How to change OnTriggerEnter to Ui Button click

Hello, Im trying to make shop system with inventory (using Invector). Invvector has a code wich adds items into your inventory, but that code is based on OnTriggerEnter(). I want to make that code to work, when i press Buy button in my shop. I tried to do OnMouseDown(), but that didnt worked. Please, can you help me?

using UnityEngine; using System.Collections; using Invector.ItemManager;

public class vAddItemByID : MonoBehaviour { public int id, amount; public bool autoEquip; public bool destroyAfter;

     void OnTriggerEnter(Collider other)
     {
         if (other.gameObject.CompareTag("Player"))
         {
             var itemManager = other.gameObject.GetComponent<vItemManager>();
             if (itemManager)
             {
                 var reference = new ItemReference(id);
                 reference.amount = amount;
                 reference.autoEquip = autoEquip;
                 itemManager.AddItem(reference);
             }
             if (destroyAfter) Destroy(gameObject);
         }
     }


    
 }