Is there a way to attach attachments using REST/SOAP API in change order

Hi team

We have a need to attach files to OPEN Purchase Orders.So we need to do a change Order by REST or Web Service to attacht these files.

We are using changePurchaseOrder Operation of PurchaseOrderServiceV2 SOAP API but using that we are able to make changes in fields but cannot attach files to Change order.

WSDL used : https://****.oraclecloud.com/fscmService/PurchaseOrderServiceV2?WSDL

Is there a way to attach files in a change order by REST or WEB Service API? Or is another way that isn't manual?

Best Regards

Rafael