How to stop instantiate spawn ?

Anybody know how can i stop cloning object when the game finish / times up ? I'am using InvokeRepeating to clone object, this is the script :

 using UnityEngine;
 using System.Collections;
 
 public class SpawnerScript : MonoBehaviour {
 
     public float spawnTime = 5f;
     public float spawnDelay = 3f;
     public GameObject[] myPrefab;
 
     void Start () {
         InvokeRepeating ("Spawn", spawnDelay, spawnTime);
     }
 
     void Spawn() {
         // Instantiate a random prefab
         int notPrefabIndex = Random.Range (0, myPrefab.Length);
         Instantiate (myPrefab [notPrefabIndex], transform.position, transform.rotation);
     }
 
 }    

Thanks before..