My knockback script is not working

My code doesn't work. When I collide with an object nothings really happening, I made sure that my objects box collider is checked to isTrigger, and I also increase the explosionStrength. What am I doing wrong could anyone help?

      public class Knockback : MonoBehaviour {

  public float explosionStrength = 10.0f;
 
  void OnTriggerEnter2D (Collider2D target_){
          Vector3 forceVec = -target_.GetComponent<Rigidbody2D>().velocity.normalized * explosionStrength;
      target_.GetComponent<Rigidbody2D>().AddForce(forceVec,ForceMode2D.Force);
   }
 }