Classes can be added to the ‘li’ tag of each menu item. This field is hidden by default. To show the classes field, navigate to Appearance > Menus. Then click the Screen Options tab at the top the screen. Click the checkbox next to CSS Classes.
When specifying class names it is not necessary to use a .
. Multiple classes can be specified by placing a space between each class name. E.g.:
menu-separator my-class