Azure ARC is a suite of products offered by Microsoft to monitor and manage VMs that are not in Azure. ARC includes the option to receive updates for old operating systems as Windows Server 2012.
As of now there’s no way to massively associate an Extended Software Update license to onboarded VMs, therefore I’m sharing 2 powershell scripts to make your life easier!
https://github.com/lucapisano/ArcESU
Please feel free to contribute to the repo!