[Unity5 C#] OnTriggerEnter not working

 using UnityEngine;
 using System.Collections;
 
 public class packs : MonoBehaviour {
     [SerializeField]
     private GameObject pack;
     [SerializeField]
     private GameObject sPoint;
 
     void OnTriggerEnter(Collider toxunan)
     {
         if(toxunan.gameObject.tag=="Player")
         {
             Instantiate(pack, sPoint.transform.position , sPoint.transform.rotation);
             Destroy(this.gameObject);
             Destroy(sPoint);
         }
     }
 }

Please help me how to fix this ?