Restricting a Nav Menu Item
In order to restrict nav menu items, you must be on the Menus admin page.
Restrictions cannot be set when editing menus via the Customizer.
When you open a nav menu item with the Restrictions plugin active, you will be presented with some new options.
Use the Viewable By field to require users to be either logged in or not logged in to view the menu item. Set to "Authenticated Users only" to show this item to users who are logged in, "Guests only" to show this item to users who are not logged in, or leave as "Everyone" to show this item to all users, regardless of login status.
In order to restrict a nav menu item by user role, use the checkboxes under the Required Roles field.
Be sure to click the Save Menu button when you are done with your changes.