To back up a web app, you need to configure a custom backup that specifies a storage account and a container as the target for the backup1. The storage account must be in the same subscription as the web app, and the container must be accessible by the web app2. The backup size is limited to 10 GB, and the backup frequency can be configured to minimize costs.
According to the table, storage1 is the only storage account that meets these requirements. Storage1 is in the same subscription and region as the web app, and it is a general-purpose v2 account that supports custom backups. Storage2 and storage3 are in a different region than the web app, which may incur additional costs for data transfer. Storage4 is a FilesStorage account, which does not support custom backups.
Therefore, you should use storage1 as the target for the backup of your web app. To configure a custom backup, you can follow these steps:
In your app management page in the Azure portal, in the left menu, select Backups.
At the top of the Backups page, select Configure custom backups.
In Storage account, select storage1. Do the same with Container.
Specify the backup frequency, retention period, and database settings as needed.
Click Configure.
At the top of the Backups page, select Backup Now.