Hey there whorobin,
The Duo Splunk Connector was built for Splunk Enterprise and works best there but I just tested that you should be able to manually add the Duo Splunk Connector to Splunk Light. You won't be able to take advantage of any of the prebuilt dashboards since we use a macro instead of an index in our searching but but you will get the Duo Data input and will be able to pull in Duo logs.
To do that:
From there you can follow the directions in the docs to get the connector setup.
I'm sorry but I'm having alot of trouble with this step. It seems as though this would work in Linux but not on Windows, which is what I am using. Is there a way to use the SPL file to link up with Splunk Light on a Windows server?