How to call OnTriggerEnter2D

What you're doing is using OnTriggerEnter2D.

This is incorrect. OnTriggerEnter2D only runs when an object enters the trigger.

Therefore you need to press L on the exact same frame that the enemy enters your trigger... Unrealistic for a human's reaction time.

Try this instead

 private void OnTriggerStay2D(Collider2D collision)
 {
    if(Input.GetKeyDown(KeyCode.L))
    {
        Destroy(collision.gameObject);
    }
 }

The difference between these two is that OnTriggerStay2D will be called every frame that your enemy is inside the trigger, instead of just being called on the first frame.

Hope you are looking for this

     void OnTriggerStay2D(Collider2D other){
      if(Input.GetKeyDown(KeyCode.L)){
         Destroy(other.gameObject)
     }
   }

Hmmm. I also tried that before and it didn't work. Without the "if" statement, it works fine. I'm not sure why it isn't working still....

Hi, Try like this.

     //Boolean to check if sword is inside or not
     bool m_IsSwordInside = false;
 
     //Update is called once per frame
     void Update()
     {
         if(Input.GetKeyUp(KeyCode.L) && m_IsSwordInside)
         {
             Destroy(other.gameObject);
         }
     }
 
 
     void OnTriggerEnter2D(Collider2D other)
     {
         //State sword is inside
         m_IsSwordInside = true;
     }
 
 
     void OnTriggerExit2D(Collider2D other)
     {
         //State sword is no longer inside
         m_IsSwordInside = false;
     }

Hope it helps!