Automated backups provided by the managed instance is correct.

The managed instance includes built in automated backups that capture full, differential, and transaction log backups so you can perform point in time restores and configure long term retention without creating custom jobs. Using the automated backup capability reduces operational overhead and it is the simplest way to ensure backups for a mid sized retailer like Orion Retail.

Create a scheduled SQL Agent job to perform database backups is not the simplest option because it requires you to build and maintain custom jobs and schedules when the managed service already performs automated backups.

Manually export database backups to an Azure Storage account is possible but it is labor intensive and error prone for regular backups. Manual exports do not provide the automated point in time restore experience that the managed instance backup system gives you.

Azure Backup is a separate service and it is not required for the managed instance automated backup scenario. Azure Backup adds extra configuration and complexity when the managed instance natively provides automated backups and retention controls.

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