How to use AP property of the stamp type annotation in javascript

I have been trying to insert a stamp using the AddAnnot method and this is the code I have:

Function Doug(FileName, path) As Long

Dim Acroapp As Acrobat.Acroapp

Dim Doc1 As Acrobat.AcroPDDoc

Dim CodeBox As Acrobat.AcroPDAnnot

Dim Page As Acrobat.AcroPDPage

Dim Cod1 As Acrobat.AcroPDDoc

Dim gap As Acrobat.AcroPDPage

Dim annot As Object

Dim prop As Object

Dim jso As Object

Dim arr(0 To 3) As Integer

Set Acroapp = CreateObject("AcroExch.App")

Set Doc1 = CreateObject("AcroExch.PDDoc")

'Set Cod1 = CreateObject("AcroExch.PDDoc")

arr(0) = 0

arr(1) = 0

arr(2) = 300

arr(3) = 300

If Doc1.Open(path & FileName) = True Then

Set Page = Doc1.AcquirePage(0)

Set jso = Doc1.GetJSObject

If Not jso Is Nothing Then

     Set annot = jso.AddAnnot()

     Set prop = annot.GetProps

          prop.Type = "Stamp"

     annot.setprops prop

     Set prop = annot.GetProps

          prop.AP = "#kZBRdNJ8NdlGCzWSCKIn3A"

          prop.rect = arr

     annot.setprops prop

End If

Doc1.Save 1, path

Doc1.Close

End If

End Function

It adds an annotation, but its just a box with no text in it. What am I doing wrong?