// Start is called before the first frame update
 void Awake()
 {
     if (i == null)
     {
         i = this;
     }
 }
    public void GetReward() //use this for onclick button
    {
        LastChestOpen = (ulong)DateTime.Now.Ticks;
        PlayerPrefs.SetString("LastChestOpen", LastChestOpen.ToString());
        chestButton.interactable = false;

        //give reward to user here
        //example i added coin
        CurrentCoin.AddCoin(5);
    }