OData REST API - Purchase Order Line -> Pre-Posting and Project connection API

Dear Community, 

We try to connect IFS Apps10 Purchase Order and Lines to Dell Boomi via API calls. We would like to create PO Lines in Apps10 with Boomi, and everything works fine only 2 things are missing. We would like to send: 

1. Pre-Posting information for PO line (code part b)
2. Project connection information to PO Line (activity level)

Our issue is we didn’t find the projection what we should use. We tried to debug with Aurena debug consol, but it didn’t help. 

Do you have any suggestion which projection should we use?

Thank you very much in advance for every suggestion or opinion. 

Kind regards, 

Balazs