How to fix some of location have more than 1 object?

I create a random gameobject by using spot location but some of location have more than 1 object, I just want to have only 1 object in 1 location

 public class QtAtRandomLocation : MonoBehaviour
 {
     [Header("QT Event")]
     public GameObject[] objectsToSpawn;
     public Transform[] spawnPoints; // An Vector3 array can also be used
     public List<GameObject> spawnedObjects; // Containing all spawned Objects; Using List to simply call .Add(GameObject);
     public int spawnCount; // How many objects should be spawned
     private int objectIndex; // Random objectsToSpawn index
     private int spawnIndex; // Random spawnPoints index
     private void Start()
     {
         // Use this for loop to not hardcode the spawn count
         for (int i = 0; i < spawnCount; i++)
         {
             // For each iteration generate a random index; You could make an int array containing if an object already got spawned and change the index.
             objectIndex = Random.Range(0, objectsToSpawn.Length);
             spawnIndex = Random.Range(0, spawnPoints.Length);
             // Instantiate object
             GameObject go = Instantiate(objectsToSpawn[objectIndex], spawnPoints[spawnIndex].position, Quaternion.identity);
             // Add Object to spawnedObjects List
             spawnedObjects.Add(go);
         }
     }
     /// <summary>
     /// Draws a Sphere at each spawnPoints position
     /// </summary>
     private void OnDrawGizmos()
     {
         Gizmos.color = Color.blue;
         for (int i = 0; i < spawnPoints.Length; i++)
         {
             Gizmos.DrawSphere(spawnPoints[i].position, 0.5f);
         }
     }
 }