You set yourself to looking by using
!set looking true
command. You can use
!set looking false
to turn looking status off. If you're not looking you won't appear in matchmaking and no one will be able to challenge you using
!challenge
command.
Bot also respects your F-Chat status . To be considered looking, your F-Chat status has to be set to either Online or Looking. If you set it to Away, Busy or DND - bot will not bother you with matchmaking or anything.