Options don't appear in Settings area

Most likely you have not met the requirements for it to work. The description says “This plugin only works under the following conditions: 1. the theme has registered at least one menu location 2. user has created at least one custom menu with one or more menu items.

If those 2 conditions are met, then the edit page for every page and post and custom post type will contain a meta box listing the custom menus with radio buttons. All you need do is select which custom menu should display when that page is called.”