Final Document Does not Include Attachment

Hello, whenever I send a document for signature and I add in an attachment, the final signed version does not include in the attachment. EG I have file 1 and file 2. File 1 contains the signature requests but file 2 does not. After all parties sign the document, the finalized signed document only contains file 1 but not file 2. Is there a way to have Box export both the finalized signed file 1 and file 2 combined into one PDF automatically?