Collision not works

Question

I want to if player collision to enemy, it shows the debug. But its not working please Help...

public class Hasar : MonoBehaviour { public float can;

// Start is called before the first frame update
void Start()
{
    
}

// Update is called once per frame
void Update()
{
    Debug.Log("Ates et!!!");
    
}

void onCollisionEnter(Collision col){
    
    if(col.gameObject.tag == "Player")
       Debug.Log("Ates kesss!!!");
       can = can - 10;
}

}