Awesome! Much nicer way to change server settings. Also don't worry that the options on the right are greyed out (they can be changed when you put a server password) as the creator has 'disabled pitstop and driving aid panels, because these settings are ignored by public servers anyway'.
Dedicated server files can be found in steam tools library to download (steam LIBRARY > near top left just below 'home' there's dropdown menu 'GAMES, SOFTWARE' and enable tools, it will now be visible in your games list for download. Install app in the new root folder common\Assetto Corsa Competizione Dedicated Server\server , then watch the tutorial on port forwarding
ps. also if you were wondering like me, the 'hourOfDay' can only be set to the hour, so you can't start a server at for example 5:30pm (this is kunos problem, not the app)