Account dimension mapping

Hi,

I am working on the "Map Model to OData Entities and Acquire Data" card (step/task) of the "Gain Insights through NexGen Procurement Analytics" mission of the SAP Discovery Center. My issue with this step is that I am not able (don't know how) to map the "Account" dimension that all the provided models have. The same for the Measures.

Can someone give some details or show me what should I do?