You will to contact a HP sales person about this. At minimum, you would need a Cell Manager-Single Drive license, p/n 6951 (UNIX) or 6961 (Windows). The sales person probably has a pre-sales specialist to evaluate your backup needs and to help with you getting the licenses that you need
If you go to the web site
www.hp.com/go/dataprotectorand
click on the 'Contact Us' button, there will be several ways to reach Sales. They should be able to provie you with part numbers, and proces of the licenses and support contracts
Once you have purchased the licenses and support level, you will be issued a Software Agreement ID (SAID), from which you can log into the support site using HP Passport