Working with CAD family parts in SW 2024 and 3Dexperience.

When using the macro below, in SolidWorks parts, it's saying "property added" but it's not.

What do I need to change when I want to add a property to the active configuration/physical product only?

Dim swApp As Object
Dim Part As ModelDoc2
Dim mExt As ModelDocExtension
Dim propMgr As CustomPropertyManager

Sub main()
Set swApp = Application.SldWorks
Set Part = swApp.ActiveDoc
Set mExt = Part.Extension
Set propMgr = mExt.CustomPropertyManager("")

Dim value As Integer
'Replace  with what you want your custom property to be called.
'Replace  with what you want the custom property to be.
'value = propMgr.Add3("PropertyName", swCustomInfoType_e.swCustomInfoText, "PropertyValue", 
swCustomPropertyAddOption_e.swCustomPropertyOnlyIfNew)
value = propMgr.Add3("Galvanisation", swCustomInfoType_e.swCustomInfoText, "X", swCustomPropertyAddOption_e.swCustomPropertyDeleteAndAdd)
If value = 0 Then
swApp.SendMsgToUser2 "Property added sucessfully.", swMbWarning, swMbOk
Else
swApp.SendMsgToUser2 "There was error adding the property.", swMbWarning, swMbOk
End If
End Sub