Retrieves and adds loan documents from a DocMagic vault.
This endpoint will only kick off the asynchronous process of retrieving documents from the external source.

The "processing" response indicates that the asynchronous job was successfully kicked off.

To determine whether or not the external documents were successfully retrieved and added to the transaction, you can use the Retrieve Transaction API to see if the documents are listed for the transaction in question, or you can check the the transaction's documents in the UI.