Create custom declaration in ABAP

Hi colleagues,

I managed to create from scratch a custom declaration using fm /SAPSLL/CUSTOMS_DOC_CREATE in GTS.

This custom declaration should use the data of an outbound delivery (but with a lot of modifications and sumarizations) from ERP.
I would like to ask for your help to identify an BAdi or enhancement point in GTS, right after the Customs delivery document is
saved, in order to trigger the new fm. Could you please help me with this?

Basically, when an outbound delivery is created in ERP, a Customs delivery document is created in GTS. Then, I must create a
new Custom Declaration. So I’m looking for a point in which to insert my logic, where reference number is available.

Thank you and kind regards,

Mihai