Import requisition process requires approver in API

Summary:

We are trying to generate requisitions in Self Service Procurement using a WS for the Import requisition process.

We submit the WS and generate the requisition in Oracle Cloud. However, the requisition exception report displays us an error message indicating the following:
<You must provide a valid approver for requisitions that are already approved>

I reviewed several notes in MOS (attached below); however, this is not generating our issue.

Do you have any advice on how we can fix this issue?

Thanks,

PRC: SSP: Requisition Approval Error Message to Approver: Invalid Action on Workflowtask (Doc ID 2774812.1)
PRC:SSP: Approver Gets "Invalid Action on Workflow Task" Error Notification (Doc ID 2142347.1)