How to send external attachment with invoices in Oracle Fusion

 Please follow the below steps and retry running the Print Receivables job after.

Please pass the following SQL Query in the Transaction Delivery Bursting > Attachment tab.
Attachment Repository = FA_UCM_PROVISIONED

SQL Query: 
-----------------
SELECT del.customer_trx_id || '_' || del.payment_schedule_id AS "KEY",
doc.DM_VERSION_NUMBER AS "ATTACHMENT_ID"
FROM AR_BPA_DELIVERY_DETAILS del,
fnd_attached_documents att,
FND_DOCUMENTS_VL doc
WHERE att.entity_name = 'RA_CUSTOMER_TRX_ALL'
AND att.pk1_value = TO_CHAR(del.CUSTOMER_TRX_ID)
AND doc.DOCUMENT_ID =att.DOCUMENT_ID
AND att.Category_Name IN
(SELECT Lookup_Code
FROM Fnd_Lookups
WHERE LOOKUP_TYPE = 'AR_PRINT_ATTACHMENT_CATEGORIES'
AND ENABLED_FLAG = 'Y'
AND (TRUNC(SYSDATE) BETWEEN nvl(Start_Date_Active,TRUNC(SYSDATE)) AND nvl(End_Date_Active,TRUNC(SYSDATE)))
)

The Print Receivables Transactions process prints transaction attachments that satisfy the following criteria:

• The transaction delivery method is Paper or Email.
• The attachment is in PDF format.
• The attachment is attached to the transaction header.
• The attachment category is defined as an active lookup code of the AR_PRINT_ATTACHMENT_CATEGORIES lookup type (Categories of Attachments to be Printed).