You are trying to fetch the Employee Central workflow records using SuccessFactors OData API and you need to know some entities that can be used to view the same data you can see in the user interface.
Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.
SAP SuccessFactors OData API - Employee Central
You can find details and samples in the Employee Central OData reference handbook chapter 16.
In this KBA, we are going to provide samples of two entities: WfRequestUIData and getWorkflowPendingData (Public Beta).
And also one direct URL to access the WF in the UI (this was taken from the API response above).
Using these entities above you can fetch EC WF data to be consumed externally.
Download, how to, Retrieve Employee Central Workflow records using OData API entities WfRequestUIData and getWorkflowPendingData, SuccessFactors HXM HCM Suite, WF, pending records, entries, view, fetch , KBA , LOD-SF-INT-EC , Employee Central SFAPI & OData Entities , LOD-SF-INT , Integrations , How To