Stockitem(IN202500) screen Price/cost tab added CurrentCost Filed Not Save in database

How to save currentCost filed in Database ?

This CurrentCost Filed is custom filed

/* DAC */

namespace PX.Objects.IN
{
    public class INItemCostExt : PXCacheExtension<PX.Objects.IN.INItemCost>
    {
        public static bool IsActive() => true;
        #region UsrCurrentCost
        [PXDBPriceCost(BqlField = typeof(INItemCostExt.usrCurrentCost))]
        [PXUIField(DisplayName = "Current Cost")]
        [CurySymbol]
        public virtual Decimal? UsrCurrentCost { get; set; }
        public abstract class usrCurrentCost : PX.Data.BQL.BqlDecimal.Field<usrCurrentCost> { }
        #endregion
    }
}

/* InventoryItemMaint_Extension */ Bussiness Logic
;

namespace PX.Objects.IN
{
    public class InventoryItemMaint_Extension : PXGraphExtension<PX.Objects.IN.InventoryItemMaint>
  {
        public static bool IsActive() => true;
        #region Event Handlers
        protected void INItemCost_RowInserted(PXCache cache, PXRowInsertedEventArgs e, PXRowInserted InvokeBaseHandler)
        {
            if (InvokeBaseHandler != null)
                InvokeBaseHandler(cache, e);
            INItemCost row = (INItemCost)e.Row;
            INItemCostExt itemCostExt = row.GetExtension<INItemCostExt>();
        }

        protected void INItemCost_RowPersisted(PXCache cache, PXRowPersistedEventArgs e, PXRowPersisted InvokeBaseHandler)
        {
            if (InvokeBaseHandler != null)
                InvokeBaseHandler(cache, e);
            INItemCost row = (INItemCost)e.Row;
            INItemCost INItemCost = (INItemCost)Base.ItemCosts.Cache.Current;
            INItemCostExt itemCostExtBase = INItemCost.GetExtension<INItemCostExt>();
        }

        protected void INItemCost_RowUpdated(PXCache cache, PXRowUpdatedEventArgs e, PXRowUpdated InvokeBaseHandler)
        {
            if (InvokeBaseHandler != null)
                InvokeBaseHandler(cache, e);
            INItemCost row = (INItemCost)e.Row;
            INItemCostExt itemCostExt = row.GetExtension<INItemCostExt>();
            INItemCost INItemCost = (INItemCost)Base.ItemCosts.Cache.Current;
            INItemCostExt itemCostExtBase = INItemCost.GetExtension<INItemCostExt>();

        }
        #endregion
    }
}

Thank You..