Did that, but didn't find anything. However, that doesn't mean there isn't a command to do it like other games.
Like: /shortcut <hotbar> <slot> "command", so it would be /shortcut 3 1 "Join Conversation" to put it on hotbar 3 slot 1...
I don't know it this game is sophisticated enough to have a command language like most others, but I thought I would ask.