"Yes, Windows Server containers are available on AKS. To run Windows Server containers in AKS, you create a node pool that runs Windows Server as the guest OS. Windows Server containers can use only Windows Server 2019. To get started, see Create an AKS cluster with a Windows Server node pool.
Windows Server support for node pool includes some limitations that are part of the upstream Windows Server in Kubernetes project. For more information on these limitations, see Windows Server containers in AKS limitations."
Source :Azure Documentation FAQ Link