Is there a way for External requisition systems to use Requisition approval rules

Summary:

Is there a way for External requisition systems to use the Requisition approval rules defined in Oracle without creating the requisition in Oracle

Content (please ensure you mask any confidential information):

Most of our requisitions are created in Oracle and use the requisition approval rules setup in the system.

We have an external requisitioning system and we do not import these requisitions into Oracle but we have a requirement to use the approvals functionality as per the approval routing and conditions as setup in Oracle. The external system does not have a custom approval workflow solution and we do not want to build an replicate the same there as well.