Create an Approval Workflow Item

Hi

New guy to workflow here. I am trying to create a workflow where based on user decision (approve or reject), we want to trigger custom actions (ABAP code).

I have created a workflow, created a user decision for it. On assigning a task to the Approval Step - I want to add a business object.

Any suggestions on which BO to be added to this task? I want to use standard BOs for this workflow.

Events will be triggered manually with ABAP (SAP_WAPI_CREATE_EVENT).