I think there is a bit of manual work to do here, you have to apply the ies profile to a material that is already on an object. So, for example, add a sphere geometry from the edit menu, double click the object in the scene tree to open the material, switch the material type to IES, click the little tiny folder icon and open the ies profile from there, or I think you can drag and drop the ies file into the path box. Then click on the disk icon in the material editor to save the material as a material into your library.
There might be an easier way, I'm not sure. This is how I've had to do it with the few LED ies profiles I've had to create.