This is linked with WTN Match Play within the programming module - not tournaments module.
Step 1: Set up the round-robin events in the Serve Tennis admin pages
Creating WTN Match Play Adult and Junior WTN Match Play in Programming
Step 2: Download the App to manage your Round Robin
You can do this from the app stores (iOS and Android) and search for USTA Serve
Step 3: Once downloaded, login to your app using your USTA username and password. Search for the start date of the event you have created.
You will then enter into the schedule view where you can view all of the upcoming sessions you set up in the Match Play, Programming module by clicking through the dates on your schedule.
See: WTN Match Play App - Managing a Match Play Program