function OnCollosionEnter problems

so I have this script so that when the player touches a key, it changes a variable from 0 to 1 and destroys the key. but for some reason, I can't get unity to recognize the collision between the player and the key.

i made a script

 function OnCollisionEnter (col : Collision)
 {
         Debug.Log("hit!");
 
 }

and what this did was show me everything that the player was colliding with. and it worked on everything except for the object of my key (which is just a sphere)

this is my full code for what i want to happen when the player gets the key

 var locklevel : int = 0;
 var keyGet : AudioClip;
 
 function OnCollisionEnter (col : Collision)
 {
     if(col.gameObject.name == "aKey")
     {
         Debug.Log("hit!");
         locklevel = 1;
         audio.PlayOneShot(keyGet);
         Destroy(col.gameObject);
     }
 
 }
 

this script is attached to the first person controller prefab. why won't it recognize a collision with the key? (the key is also instantiated and not placed from the beggining, if that makes a difference)