PS: the "plus menu" as NanaFreak calls it
(I would call it the plus! icon button), is the Plus! icon you see on the buttonbar in the contactlist under your display picture and/or on the formatting toolbar in a conversation.
Click on those icons, and scripts which are active and which have a menu (this depends from script to script) will be listed there. Quite often it is from here that you can access the script's configurations dialogs or other direct settings/commands.
Now it is possible that you don't see these Plus! icon buttons. In that case you need to enable them:
- for the contactlist, enable:
Plus! > Preferences > Messenger > Main > Plus! shortcut > Add Messenger Plus! buttons in the contact list
- for the conversation window, enable:
Plus! > Preferences > Conversations > Main > Add Messenger Plus! buttons in the toolbar