Unfortunately, if you are looking for a technician manual for the scheduled maintenance Ducati charges about $600 for a USB stick with the manual on it. That's what threads back in 2013 are saying at least. I found a CD key on Ebay for the Monster 821; I assume if someone ordered it they would get a CD or USB.
I did a search and it seems any Ducati after 2010 will have the technician/service manuals loaded on USB sticks. Here's why "Ducati Motor Holding, has determined that there is too much liability to supply, Factory Service Manuals, to non factory certified technicians, that are not in possession of Ducati specific tools."