Adding a Custom Post Type into the menu screen

To get your custom post types to show up in Appearance -> Menus, you need to do two things:

  1. Check your arguments and make sure that show_in_nav_menus is set to true.
  2. Go to the Appearance -> Menus page and at the very top, click on Screen Options. In the panel that opens, make sure that your custom post types are checked.