I have a user defined field in customer screen (LocationExt.usrExpectedPaymentDate) as below,

User Defined Field in Customer Screen

I need to access this field for a calculation in the sales order entry graph but I get this error.

[2024-10-23 04:45:10.957] App_CodeCachesSOOrderEntry.cs(159): error CS0246: The type or namespace name ‘StandaloneLocationExt’ could not be found (are you missing a using directive or an assembly reference?)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using PX.Common;
using PX.Data;
using PX.Objects.AP;
using PX.Objects.AR;
using PX.Objects.CA;
using PX.Objects.CM;
using PX.Objects.CR;
using PX.Objects.CS;
using PX.Objects.DR;
using PX.Objects.EP;
using PX.Objects.GL;
using PX.Objects.IN;
using PX.Objects.PM;
using PX.Objects.PO;
using PX.Objects.TX;
using POLine = PX.Objects.PO.POLine;
using POOrder = PX.Objects.PO.POOrder;
using PX.CarrierService;
using PX.Concurrency;
using CRLocation = PX.Objects.CR.Standalone.Location;
using PX.Objects.AR.CCPaymentProcessing;
using PX.Objects.AR.CCPaymentProcessing.Common;
using PX.Objects.AR.CCPaymentProcessing.Helpers;
using PX.Objects.AR.CCPaymentProcessing.Interfaces;
using ARRegisterAlias = PX.Objects.AR.Standalone.ARRegisterAlias;
using PX.Objects.AR.MigrationMode;
using PX.Objects.Common;
using PX.Objects.Common.Discount;
using PX.Objects.Common.Extensions;
using PX.Objects.IN.Overrides.INDocumentRelease;
using PX.CS.Contracts.Interfaces;
using Message = PX.CarrierService.Message;
using PX.TaxProvider;
using PX.Data.DependencyInjection;
using PX.Data.WorkflowAPI;
using PX.LicensePolicy;
using PX.Objects.Extensions.PaymentTransaction;
using PX.Objects.SO.GraphExtensions.CarrierRates;
using PX.Objects.SO.GraphExtensions.SOOrderEntryExt;
using PX.Objects.SO.Attributes;
using PX.Objects.Common.Attributes;
using PX.Objects.Common.Bql;
using OrderActions = PX.Objects.SO.SOOrderEntryActionsAttribute;
using PX.Objects.SO.DAC.Projections;
using PX.Data.BQL.Fluent;
using PX.Data.Localization;
using PX.Data.Reports;
using PX.Objects.IN.DAC.Accumulators;
using PX.Data.BQL;
using PX.Objects.SO.Standalone;
using PX.Objects;
using PX.Objects.SO;
using CFMWT22072024;

namespace PX.Objects.SO
{
  public class SOOrderEntry_Extension : PXGraphExtension<PX.Objects.SO.SOOrderEntry>
  {
    #region Event Handlers
protected void SOLine_UsrAnticipatedInvDate_FieldUpdated(PXCache sender, PXFieldUpdatedEventArgs e)
{
     var row = e.Row as SOLine;
            if (row == null) return;

            // Fetch the Sales Order
            SOOrder order = PXSelect<SOOrder,
                Where<SOOrder.orderNbr, Equal<Required<SOOrder.orderNbr>>>>
                .Select(Base, row.OrderNbr);
            if (order == null) return;

            // Fetch the Terms
            Terms terms = PXSelect<Terms,
                Where<Terms.termsID, Equal<Required<Terms.termsID>>>>
                .Select(Base, order.TermsID)
                .RowCast<Terms>()
                .FirstOrDefault();
            if (terms == null) return;

            // Get the anticipated invoice date from SOLine
            SOLineExt soLineExt = sender.GetExtension<SOLineExt>(row);
            DateTime? anticipatedInvoiceDate = soLineExt.UsrAnticipatedInvDate;
            if (anticipatedInvoiceDate == null) return;

            // Get the payment terms days
            int termsDays = terms.DayDue00.GetValueOrDefault();

            // Fetch the Location
            //Location location = PXSelect<Location,
            //    Where<Location.bAccountID, Equal<Required<Location.bAccountID>>,
             //   And<Location.locationID, Equal<Required<Location.locationID>>>>>
            //    .Select(Base, order.CustomerID, order.CustomerLocationID)
             //   .RowCast<Location>()
             //   .FirstOrDefault();
            //if (location == null) return;

            // Get the Location extension to access custom fields
           // LocationExt locationExt = PXCache<Location>.GetExtension<LocationExt>(location);
            // Fetch the Location using the CRLocation alias
    CRLocation location = PXSelect<CRLocation,
        Where<CRLocation.bAccountID, Equal<Required<CRLocation.bAccountID>>,
        And<CRLocation.locationID, Equal<Required<CRLocation.locationID>>>>>
        .Select(Base, order.CustomerID, order.CustomerLocationID)
        .RowCast<CRLocation>()
        .FirstOrDefault();
    if (location == null) return;

    // Get the Location extension to access custom fields
    StandaloneLocationExt locationExt = PXCache<CRLocation>.GetExtension<StandaloneLocationExt>(location);

            if (locationExt?.UsrExpectedPaymentDate == null) return;

            // Get the additional days from the Location UDF
            int additionalDays = locationExt.UsrExpectedPaymentDate.Value.Day;

            // Calculate the final expected payment date:
            // Anticipated Invoice Date + Terms Days + Additional Days from Location
            DateTime expectedPaymentDate = anticipatedInvoiceDate.Value
                .AddDays(termsDays)
                .AddDays(additionalDays);

            // Update the expected payment date in the SOLine
            sender.SetValueExt<SOLineExt.usrExpectedPaymentDate>(row, expectedPaymentDate);
}
}
}

How can I access this field in order to process my calculation?

Any help would be appreciated, thank you!