Box 1: A Recovery Services vault
You can set up a Recovery Services vault and configure backup for multiple Azure VMs.
Box 2: A backup policy -
In Choose backup policy, do one of the following:
- Leave the default policy. This backs up the VM once a day at the time specified, and retains backups in the vault for 30 days.
- Select an existing backup policy if you have one.
- Create a new policy, and define the policy settings.
Reference:
https://docs.microsoft.com/en-us/azure/backup/backup-azure-vms-first-look-arm