Scriptum/Assets/Scripts/SceneManager/SaveInventory/SaveInventorySystem.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

public class SaveInventorySystem : MonoBehaviour
{
    public static void SaveInventoryItemsList(Dictionary<int, EquippableItemPrefarbAsset> equitabbleItemList, string ElementName)
    {
        BinaryFormatter formatter = new BinaryFormatter();
        // todo: add in scene name folder
        string path = SaveSystem.GetSavePath(); 
Debug.Log("Saved Inventory at " + path);
        if (!Directory.Exists(path))
            Directory.CreateDirectory(path);
        
        path += "/" + ElementName + ".fun";

        FileStream stream = new FileStream(path, FileMode.Create);

        Dictionary<int, EquippableItemPrefarbAssetData> data = new Dictionary<int, EquippableItemPrefarbAssetData>();

        foreach(KeyValuePair<int, EquippableItemPrefarbAsset> equitabbleItemEntry  in equitabbleItemList)
        {
            data[equitabbleItemEntry.Key] = new EquippableItemPrefarbAssetData(equitabbleItemEntry.Value);
        }

        formatter.Serialize(stream, data);
        stream.Close();  
    }

    private static void Save() 
    {

    }

    public static Dictionary<int, EquippableItemPrefarbAssetData> LoadInventoryItemsList(string ElementName)
    {
        string path = SaveSystem.GetSavePath() + "/" + ElementName  + ".fun"; 

        if(File.Exists(path))
        {
            
            BinaryFormatter formatter = new BinaryFormatter();
            FileStream stream = new FileStream(path, FileMode.Open);

            Dictionary<int, EquippableItemPrefarbAssetData> equitabbleItemList = formatter.Deserialize(stream) as Dictionary<int, EquippableItemPrefarbAssetData>;
            stream.Close();

            return equitabbleItemList;
        } else {
            Debug.Log("Save file not found in " + path);
            return null;
        }
    }

}