how I can save the data of a list of purchased items ?

I want to save the list of items purchased from a store and displayed in another list here is the store script : using UnityEngine; using UnityEngine.UI; using System.Collections.Generic;

[System.Serializable]

public class Shop : MonoBehaviour { #region Singlton:Shop

 public static Shop Instance;

 void Awake()
 {
     if (Instance == null)
         Instance = this;
     //else
     //    Destroy (gameObject);
 }

 #endregion

 [System.Serializable] public class ShopItem
 {
     public Sprite Image;
     public int Price;
     
     public bool IsPurchased = false;




     public static void SetBool(string IsPurchased, bool state)
     {
         PlayerPrefs.SetInt(IsPurchased, state ? 1 : 0);
     }

      public static bool GetBool(string IsPurchased)
     {
         int value = PlayerPrefs.GetInt(IsPurchased);

         if (value == 1)
         {
             return true;
         }

         else
         {
             return false;
         }
     }
 }

 public List<ShopItem> ShopItemsList;
 public List<ShopItem> ShopItemsListIcon;
 [SerializeField] Animator NoCoinsAnim;
 

 [SerializeField] GameObject ItemTemplate;
 GameObject g;
 [SerializeField] Transform ShopScrollView;
 
 Button buyBtn;

 void Start ()
 {
     int len = ShopItemsList.Count;
     for (int i = 0; i < len; i++) {
         g = Instantiate (ItemTemplate, ShopScrollView);
         g.transform.GetChild (0).GetComponent <Image> ().sprite = ShopItemsListIcon [i].Image;
         g.transform.GetChild (1).GetChild (0).GetComponent <Text> ().text = ShopItemsList [i].Price.ToString ();
         buyBtn = g.transform.GetChild (2).GetComponent <Button> ();
         if (ShopItemsList [i].IsPurchased) {
             DisableBuyButton ();
         }
         buyBtn.AddEventListener (i, OnShopItemBtnClicked);
     }
 }

 void OnShopItemBtnClicked (int itemIndex)
 {
     if (Game.Instance.HasEnoughCoins (ShopItemsList [itemIndex].Price)) {
         Game.Instance.UseCoins (ShopItemsList [itemIndex].Price);
         //purchase Item
         ShopItemsList [itemIndex].IsPurchased = true;

         //disable the button
         buyBtn = ShopScrollView.GetChild (itemIndex).GetChild (2).GetComponent <Button> ();
         DisableBuyButton ();
         //change UI text: coins
         Game.Instance.UpdateAllCoinsUIText ();

         //add avatar
         Profile.Instance.AddAvatar (ShopItemsList [itemIndex].Image);
     } else {
         NoCoinsAnim.SetTrigger ("NoCoins");
         Debug.Log ("You don't have enough coins!!");
     }
 }

 void DisableBuyButton ()
 {
     buyBtn.interactable = false;
     buyBtn.transform.GetChild (0).GetComponent <Text> ().text = "PURCHASED";
 }
 

}

Here is the profile script ( where the purchased items is displayed ) :

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

public class Profile : MonoBehaviour { #region Singlton:Profile

 public static Profile Instance;

 void Awake ()
 {
     if (Instance == null)
         Instance = this;
     else
         Destroy (gameObject);
 }

 #endregion

 public class Avatar
 {
     public Sprite Image;
 }

 public List<Avatar> AvatarsList;

 [SerializeField] GameObject AvatarUITemplate;
 [SerializeField] Transform AvatarsScrollView;

 GameObject g;
 int newSelectedIndex, previousSelectedIndex;

 [SerializeField] Color ActiveAvatarColor;
 [SerializeField] Color DefaultAvatarColor;

 [SerializeField] Image CurrentAvatar;
 

 void Start ()
 {
     GetAvailableAvatars ();
     newSelectedIndex = previousSelectedIndex = 0;
 }

 void GetAvailableAvatars ()
 {
     for (int i = 0; i < Shop.Instance.ShopItemsList.Count; i++) {
         if (Shop.Instance.ShopItemsList [i].IsPurchased) {
             //add all purchased avatars to AvatarsList
             AddAvatar (Shop.Instance.ShopItemsList [i].Image);
         }
     }

     SelectAvatar (newSelectedIndex);
 }

 public void AddAvatar (Sprite img)
 {
     if (AvatarsList == null)
         AvatarsList = new List<Avatar> ();
     
     Avatar av = new Avatar (){ Image = img };
     //add av to AvatarsList
     AvatarsList.Add (av);

     //add avatar in the UI scroll view
     g = Instantiate (AvatarUITemplate, AvatarsScrollView);
     g.transform.GetChild (0).GetComponent <Image> ().sprite = av.Image;

     //add click event
     g.transform.GetComponent <Button> ().AddEventListener (AvatarsList.Count - 1, OnAvatarClick);
 }

 void OnAvatarClick (int AvatarIndex)
 {
     SelectAvatar (AvatarIndex);
 }

 void SelectAvatar (int AvatarIndex)
 {
     previousSelectedIndex = newSelectedIndex;
     newSelectedIndex = AvatarIndex;
     AvatarsScrollView.GetChild (previousSelectedIndex).GetComponent <Image> ().color = DefaultAvatarColor;
     AvatarsScrollView.GetChild (newSelectedIndex).GetComponent <Image> ().color = ActiveAvatarColor;

     //Change Avatar
     CurrentAvatar.sprite = AvatarsList [newSelectedIndex].Image;
 }

}