How to Add Lives to My Main Character in 2D Game?,How to Add Lives to my Main Character?

I'm making a simple game that is similar to angry birds. I watched this video to make the game: https://www.youtube.com/watch?v=Lu76c85LhGY

I want to count the number of lives that the main character uses. This is the code that I have so far for that main character:

 using System;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Bird : MonoBehaviour
 {
     [SerializeField] float _launchForce = 500;
     [SerializeField] float _maxDragDistance = 3;
 
     Vector2 _startPosition;
     Rigidbody2D _rigidbody2D;
     SpriteRenderer _spriteRenderer;
     bool _resetting;
 
     public bool IsDragging { get; private set; }
 
     void Awake()
     {
         _rigidbody2D = GetComponent<Rigidbody2D>();
         _spriteRenderer = GetComponent<SpriteRenderer>();
     }
     // Start is called before the first frame update
     void Start()
     {
         _startPosition = _rigidbody2D.position;
         _rigidbody2D.isKinematic = true;
     }
 
     void OnMouseDown()
     {
         _spriteRenderer.color = Color.red;
         IsDragging = true;
     }
 
     void OnMouseUp()
     {
         Vector2 currentPosition = _rigidbody2D.position;
         Vector2 direction = _startPosition - currentPosition;
         direction.Normalize();
 
         _rigidbody2D.isKinematic = false;
         _rigidbody2D.AddForce(direction * _launchForce);
 
         _spriteRenderer.color = Color.white;
 
         IsDragging = false;
     }
 
     void OnMouseDrag()
     {
         Vector3 mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
         
         Vector2 desiredPosition = mousePosition;
 
         float distance = Vector2.Distance(desiredPosition, _startPosition);
         if (distance > _maxDragDistance)
         {
             Vector2 direction = desiredPosition - _startPosition;
             direction.Normalize();
             desiredPosition = _startPosition + (direction * _maxDragDistance);
         }
         
         if (desiredPosition.x > _startPosition.x)
             desiredPosition.x = _startPosition.x;
 
         _rigidbody2D.position = desiredPosition;
     }
 
     // Update is called once per frame
     void Update()
     {
         
     }
 
     void OnCollisionEnter2D(Collision2D collision)
     {
         StartCoroutine(ResetAfterDelay());
     }
 
     IEnumerator ResetAfterDelay()
     {
         yield return new WaitForSeconds(3);
         _rigidbody2D.position = _startPosition;
         _rigidbody2D.isKinematic = true;
         _rigidbody2D.velocity = Vector2.zero;
     }
 }

How do I count the number of lives used by my character?

Thanks in advance, any help is appreciated!