For a deeper look into our DataScope Select SOAP API, look into:
Overview | Quickstart | Documentation | Downloads | Tutorials
When you want to find a specific data field, you should check the Data Content Guide. Open tab "Field Descriptions", and use a text filter on column D or E to display only the rows that "contain" a keyword that defines what you are looking for, in this case I'd use "Settlement Price".
The attached screenshot shows there are 19 results, split over several templates (i.e. API calls).