Thanks, I'll work on that part tonight.
Basically you're signing up your instance (adding a bot or generic user account that will be used to subscribe to the comms shared), and you add your admin username (no other information) so that it can be verified that an instance admin is the one initiating this procedure.
The bot credentials are so that it can subscribe to communities shared on Threadirator and help them federate to other instances, as discovery of new communities is not automatic requiring at least one account on an instance to manually visit/join it before it will start appearing in feeds.