Spawning unique prefabs at different transform posititions

I have this script that lets me declare how many prefabs I would like to instantiate within my scene and also define the positions that they would spawn on by using transforms.

     public class mystery_box_spawner : MonoBehaviour {
     
         public Transform[] teleport;
         public GameObject[] prefeb;
         
         void Start()
         { 
             spawnPrefab ();
     
         }
     
         public void spawnPrefab()
         {
             int tele_num = Random.Range(0,8);
             int prefeb_num = Random.Range(0,3);
             Instantiate(prefeb[prefeb_num], teleport[tele_num].position, teleport[tele_num].rotation );
     
         }
     
     }
 

What I would like to add to this however, would be the ability to have my prefabs spawn only once at a certain position and not have it duplicated and have multiple prefabs spawn at a single position which is currently what happens. Any idea how I can do that? Any help would be much appreciated, thanks so much.