This afternoon we released the third update to Azure App Service on Azure Stack. This release updates the resource provider and brings the following key capabilities:

Support for use of SQL Server Always On for Azure App Service Resource Provider databases.
Updates to App Service Tenant, Admin, Functions portals and Kudu tools.
Updates to ASP.Net Core, NodeJS, Zulu OpenJDK, Tomcat, PHP, Wincache and Git
All other fixes and updates detailed in the App Service on Azure Stack Update Three Release Notes

You can download the new installer and helper scripts:

Installer – https://aka.ms/appsvcupdate3installer
Helper Scripts – https://aka.ms/appsvconmashelpers

Please read the updated documentation prior to getting started with deployment:

Before you get started with App Service on Azure Stack
Deploy the App Service Resource Provider for new deployments
Update the App Service Resource Provider for updating existing deployments