Federated (Corporate and Education) Licenses can download and install Lightroom Desktop. However, Services need to be enabled on your license in order to use the product.
Lightroom Desktop relies on storing your catalog as well as your images in the cloud. If your license does not allow for Cloud Services, you will not be able to add photos to your Lightroom catalog and the option will be grayed-out.
If this is the case, you can contact your Adobe License Administrator and ask them if: