The Plesk Control Panel is specifically designed to only manage websites on either a Windows Server or Linux environment. You'll need to have your site administrator run the PowerServer install using their native MS-Windows account into your IIS instance.
However if you do go that route, you'll also have to make sure that the site gives you access to the PowerServer console (AWS) in order to manage the PowerServer environment. That would also include running MSI install files to deploy your mobile Apps.
Regards ... Chris