I need a line of code to stop player being destroyed when shield is on!

Hello there, I have lil problem Im still learning coding C# and I can't figure out how to stop my enemy from killing the player when it enters on Collision with it when the Player has the shield on, any thoughs on that I 'll really apreciate it.

here's my Code:

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class PlayerController : MonoBehaviour { public float moveSpeed; private Rigidbody theRB; public ParticleSystem explosionParticle; public bool hasShield = false; public bool gameOver; private Animator animator; public GameObject ShieldIndicator;

 // Start is called before the first frame update
 void Start()
 {
     theRB = GetComponent<Rigidbody>();
     animator = GetComponent<Animator>();

 }

 // Update is called once per frame
 void Update()
 {
     theRB.velocity = new Vector3(Input.GetAxis("Horizontal") * moveSpeed, theRB.velocity.y, Input.GetAxis("Vertical") * moveSpeed);

    
 }

 private void OnTriggerEnter(Collider collider)
 {

     if (collider.CompareTag ("PowerPill"))
     {

         hasShield = true;
         ShieldIndicator.gameObject.SetActive(true);
         gameObject.GetComponent<Animator>().Play("Xplosion");
         StartCoroutine(ShieldCountDownRoutine());

     }

 }

 

 private void OnCollisionEnter(Collision collision)
 {
     if (collision.gameObject.CompareTag("Enemy") && hasShield)
     {
         Rigidbody enemyRigidbody = collision.gameObject.GetComponent<Rigidbody>();
         
     }

     

     if (collision.gameObject.CompareTag("Enemy"))
     {

         

         Debug.Log("Game Over");
         gameOver = true;
         Destroy(gameObject);
         
     }

 }

 IEnumerator ShieldCountDownRoutine()
 {

     yield return new WaitForSeconds(5);
     hasShield = false;
     ShieldIndicator.gameObject.SetActive(false);
 }

}