Wait for login screen to load.
Just select a Nickname. No password is needed. Click Start.
Wait for client to connect to Undernet.
You can read more about the Brubek bot at Freelance Traveller.
The basic commands is that you write: Brubek, and then what you want Brubek to do.
A few examples:
Brubek, roll 6 6
If you have problems connecting to the chat, then try the Backdoor that uses another Chat network (otherworlders).
The Backdoor channel is called #LoneStar. It is connected with a pipe to #traveller @ Undernet.