This article is only relevant if you are unable to connect to RealVNC Server using RealVNC Viewer after installation and licensing.
The Service Mode Server dialog and icon will not appear in an RDP session, so this is why you cannot see them.
If you are receiving an "Access is Denied" error message when trying to connect to RealVNC Server, this means that the user account that you are authenticating with does not have permission to access RealVNC Server. By default, only members of the local Administrators group can access RealVNC Server.
To resolve this while connected by RDP, you will need to configure RealVNC Server using the Registry. The relevant key is
You will need to create a String value named Permissions. To determine the value for the parameter, we recommend using the VNC Permissions Creator.
For more information about the Permissions parameter please see this page.