add ship to contact to project

Hi all, i need to add ship to section to project.

I try this

public class ContractExt : PXCacheExtension<Contract>
    {
        public static bool IsActive()
        {
            return true;
        }

        #region UsrShipContactID
        public abstract class usrShipContactID : PX.Data.BQL.BqlInt.Field<usrShipContactID> { }
        [PXDBInt]
        [PXSelector(typeof(PMShippingContact.contactID), ValidateValue = false)]
        [PXUIField(DisplayName = Messages.ShippingContact, Visible = false)]
        [PMShippingContact(typeof(Select2<Customer,
            InnerJoin<PX.Objects.CR.Standalone.Location, On<PX.Objects.CR.Standalone.Location.bAccountID, Equal<Customer.bAccountID>,
                And<PX.Objects.CR.Standalone.Location.locationID, Equal<Customer.defLocationID>>>,
            InnerJoin<Contact, On<Contact.bAccountID, Equal<Customer.bAccountID>,
                And<Contact.contactID, Equal<Customer.defContactID>>>,
            LeftJoin<PMShippingContact, On<PMShippingContact.customerID, Equal<Contact.bAccountID>,
                And<PMShippingContact.customerContactID, Equal<Contact.contactID>,
                And<PMShippingContact.revisionID, Equal<Contact.revisionID>,
                And<PMShippingContact.isDefaultContact, Equal<True>>>>>>>>,
            Where<Customer.bAccountID, Equal<Current<Contract.customerID>>>>), typeof(Contract.customerID))]
        public virtual int? UsrShipContactID { get; set; }
        #endregion
    }
 

 public class ProjectEntryExt : PXGraphExtension<ProjectEntry>
    {
        public static bool IsActive()
        {
            return true;
        }

        #region Select
        [PXViewName(Messages.ShipToContact)]
        public PXSelect<PMShippingContact, Where<PMShippingContact.contactID, Equal<Current<ContractExt.usrShipContactID>>>> ShipTo_Contact;
        #endregion

        #region EventHendlers
        protected virtual void _(Events.RowSelected<PMProject> e, PXRowSelected baseMethod)
        {
            if (baseMethod != null)
            {
                baseMethod(e.Cache, e.Args);
            }

            PMProject row = e.Row;

            if (row == null)
                return;

            bool isProjectEditable = row.IsCompleted != true && row.IsCancelled != true && row.Rejected != true;

            ShipTo_Contact.Cache.AllowUpdate = isProjectEditable;
        }
        #endregion
    }

Add filds on aspx. But my field not populated when i choose customer, and i cannot set override checkbox. I try this example from PM307000 screen.