An Azure service that is used to provision Windows and Linux virtual machines.
Hello Gianfranco Lapenna,
Extended Security Updates are free for VMs in Azure. These include destinations such as Azure Virtual Machines (VMs), Dedicated Host, Azure VMware Solution, Nutanix Cloud Clusters on Azure, and the Azure Stack portfolio.
Eligible customers can use the Azure Hybrid Benefit (available to customers with active Software Assurance or Server Subscriptions) to obtain discounts on the license of Azure Virtual Machines (IaaS) or Azure SQL Database Managed Instance (PaaS).
The nested VM is not running directly on Azure infrastructure but inside a VM, it is generally not eligible for the free ESU benefit provided by Azure.
ESU supports- The Windows 10 ESU program is free for Azure VMs running Windows 10 Enterprise, Education, or Pro editions in commercial use. Virtual machines (VMs) hosted in Azure are automatically enabled for ESUs if the VM is configured to receive updates, and these updates are provided free of charge. ESU also supports for the Windows Server and SQL Server 2008 and 2008 R2 only on Azure.
ESU Availability and End Dates- https://learn.microsoft.com/en-us/lifecycle/faq/extended-security-updates#esu-availability-and-end-dates
If you have any further queries, do let us know.