Ola Hallengren - DatabaseBackup SQL Version - Backup to Azure requirements
From Microsoft's documentation: 


  Manage your backups to Microsoft Azure: Using the same methods used to
  backup to DISK and TAPE, you can now back up to Microsoft Azure
  storage by specifying URL as the backup destination. You can use this
  feature to manually backup or configure your own backup strategy like
  you would for a local storage or other off-site options. This feature
  is also referred to as SQL Server Backup to URL. For more information,
  see SQL Server Backup to URL. This feature is available in SQL Server
  2012 SP1 CU2 or later. This feature has been enhanced in SQL Server
  2016 (13.x) to provide increased performance and functionality through
  the use of block blobs, Shared Access Signatures, and striping.