Adding extension to Standard IDOC (Basic Type DELVRY03)

Hi Experts,

I am adding an extension to an IDOC , but the added extension is not visible when the IDOC is triggered.

I have referred the steps from the below link:-

**************** - IDOC Extension

I am doing it for a specific customer but when i process a delivery for that customer the segment is not coming in the data record,

Below are the screenshots of my extension and the data record where i am unable to see the extension.

Image may be NSFW.
Clik here to view.Image may be NSFW.
Clik here to view.