How to UPSERT the PDF Attachment to Successfactors using SAP HCI

Hi, I am trying to upsert the attachment in success factors for one of the field(Custom Field) in OData API. Actually, i got the PDF file from the third party response and i have to upsert that PDF File in JobApplication API. I didn't see that field from the fields list in the API(Job Application) while configuring the adapter. Do i need to attach through Attachment API? If yes, what is the procedure and what is the association between Attachment API and Job Application API?