Step 4. Specify Virtual Network Settings

At the Virtual Network step of the Create a private endpoint wizard, do the following:

From the Virtual network drop-down list, select a virtual network to which the backup appliance or worker instances are connected.
From the Subnet drop-down list, select a subnet to which the backup appliance or worker instances are connected. For a subnet to be displayed in the list, it must be created within the selected virtual network as described in Microsoft Docs.