retrieve outbound delivery number based on freight order number

I am able to see the the outbound delivery number from the document flow in freight order screen. How can I retrieve delivery number based on freight order number using abap?

Update: I found the node that contains the Outbound delivery key in TOR object.

can someone show me the code to retrieve this based on freight number?

screen-shot-2018-05-16-at-64604-pm.png

thanks