Microsoft requires a license for users which have Remote Desktop Service roles. Do I need such license for system users created by Plesk?
By default Plesk creates system users which cannot access a server via Remote Desktop and do not have any RDS role, so they do not require any additional licensing.
Plesk doesn’t install any of RDS-related Windows features and roles during installation.
Access to a server over Remote Desktop can be enabled for a system user from Plesk > Subscriptions > example.com > Hosting Settings > Access to the server over Remote Desktop
A corresponding service plan must have the Management of access to the server over Remote Desktop feature enabled in Plesk > Service Plans > <plan_name> > Permissions
Note: Remote Desktop access, uses a feature of Windows Server which can be charged separately based on Windows license used on the server.