Puedes pasar lo que tienes?
Estuve viendo en otros foros pero ya eran un poco viejos. Esto es lo que conseguí
public class CoinScript : MonoBehaviour {
//You don't use it, at least at OntriggerEnter, so you might not need it
//public GameObject PickUp;
void OnTriggerEnter(Collider col)
//You don't use this at this method PickUp at this method
//PickUp = GameObject.FindGameObjectWithTag("PickUp");
//gameobject is never null if it's not destroyed, u dont need this if.
//if (gameObject != null)
//if you want to be sure only PickUp gameObject is able to collect the coin you can do this
if(col.gameObject.tag == "PickUp")
{
// Do something
ScoreTextScript.coinAmount++;
Destroy(gameObject);
}
}
}