Kanni theme supports custom WordPress menus, with multiple levels of dropdown support for the main menu. There are 3 areas of the theme where you can assign a menu; the main menu, the Secondary Menu, and the Shortcode Menu. Each of these menu locations can have a custom menu assigned. Once a menu is created and assigned to the location, it will show up on the site. There are also several Theme Options to customize the menu.
To assign location
Navigate to Appearance > Customize > Menus > Menu Locations, click the option titled Menu Locations. Select your menu location, by clicking the dropdown menu in each option then hit the Save & Publish button.
Go to Appearance > Menus > Menu Location tab > assign your menus to the location you want > Save Changes.
NOTE: You can create submenus by dragging and dropping the items within other menu items. If you want to edit or remove a menu item, click the little arrow on the right-side of the menu item name. A selection of options will drop down, including editing the navigation label as well as removing the item altogether.