Add Documents automatically when PO creation

Hello experts,

In BADI IF_EX_ME_PROCESS_PO_CUST~CLOSE I want to link automatically to the PO the documents that are linked to the material of each item in the material master.

I have seen that maybe BAPI_PO_CHANGE could be used, in which structure is the document link? Is that the correct BAPI, if not, what BAPI should I use?

Thanks in advance.