How should I expose BAPI_ALM_NOTIF_CREATE using oData and the gateway service builder?

How should I expose BAPI_ALM_NOTIF_CREATE using oData and the gateway service builder?

If I import the RFC ( using RFC or BOR ) it creates a bunch of entities but then it expects keys for all of them.

Am I on the right track, do I just need to define key properties for these structures?

Is there an easy way to map the values passed in to make the call to the RFC?

Alternatively I could create my own RFC that calls BAPI_ALM_NOTIF_CREATE and just expose the parameters that I want to pass over, but that might be more work.