Hi,
I can't say I understand SAP's licensetypes very much, but here's was I think right:
According to LicesneGuide (comes in SAP's installation documentation), the Indirect Access license is bundled with the DI Server, meaning can be purchased with that license only.
You can grant your users the "Compatibility License for AddOns" license, but then they'll have only UI access. If your users have no other license (such professional, CRM etc), they won't be able to perform any DB task.
Beni.