Properties of API tasks are configured using the General and Document tabs.
The General tab allows you to map a list of json paths to property names that are used to set values in the Workflow property bag when an API task is executed.
If a portfolio relation does not find any work item to execute upon, the Document tab allows you to configure an API task for the newly-created Virtual E-Form. It also allows you to map json paths to keywords on the Virtual E-Form.
Similarly, when using WorkView Objects as the item type, specify the json paths to attribute values on the newly created WorkView Object.