Yes, Azure App Services are supported and the oneagent can be enabled via our site-extension. For more info please have a look on this page: https://help.dynatrace.com/infrastructure-monitori...
List of supported services is coming soon.
Generally speaking of fully managed Azure services, we will support them in upcoming Azure Monitor dashboard. In the meanwhile, you can push all required monitoring metrics directly into Dynatrace via our API or a custom-plugin.