This add-on allows your backups to be stored on your Microsoft Azure (blob storage) account (not to be confused with Microsoft OneDrive).
For the very best value, Updraft Premium includes this, plus every other Add-On (with unlimited licences) at a significant discount. Or buy Add-On licences here for the number sites you want it for.
Microsoft Azure settings:
This purchase includes access to support and updates for 1 year, after which time it is possible to renew.