Counter

using System.Collections;
using TMPro;
using UnityEngine;

public class Counter : MonoBehaviour
{
    [SerializeField] private TextMeshProUGUI _textCounter;

    private float _currentValue;
    private bool _isActive;
    private IEnumerator _coroutine;
    private WaitForSeconds _wait;

    private void Start()
    {
        _currentValue = 0f;
        _wait = new WaitForSeconds(.5f);
        _isActive = false;
        _coroutine = IncreaseValue();
    }

    public void Increase()
    {
        if (_isActive)
        {
            StartCoroutine(_coroutine);
            _isActive = false;
        }
        else
        {
            StopCoroutine(_coroutine);
            _isActive = true;
        }
    }

    private IEnumerator IncreaseValue()
    {
        while (true)
        {
            _currentValue++;
            _textCounter.text = _currentValue.ToString("");

            yield return _wait;
        }
    }
}