KTMenu is a Metronic's custom plugin defined in [metronic]/theme/default/[demo]/src/assets/js/global/components/base/menu.js.

The Metronic's Menu components allows to manage both horizontal and vertical multi level menus for both desktop and mobile modes.

The below code shows the basic vertical menu initialization with accordion submenu mode:

var asideMenu = new KTMenu(id, options);

var asideMenu = new KTMenu('kt_aside_menu', {
    // vertical scroll
    scroll: {
        height: function() {}
    },

    // submenu setup
    submenu: {
        desktop: {
            // by default the menu mode set to accordion in desktop mode
            default: 'accordion',
            // whenever body has this class switch the menu mode to dropdown
            state: {
                body: 'kt-aside--minimize',
                mode: 'dropdown'
            }
        },
        tablet: 'accordion', // menu set to accordion in tablet mode
        mobile: 'accordion' // menu set to accordion in mobile mode
    },

    //accordion setup
    accordion: {
        expandAll: false // allow having multiple expanded accordions in the menu
    }
});

The below code shows the basic horizontal menu initialization:

var headerMenu = new KTMenu('kt_header_menu', {
    submenu: {
        desktop: 'dropdown',
        tablet: 'accordion',
        mobile: 'accordion'
    },
    accordion: {
        slideSpeed: 200, // accordion toggle slide speed in milliseconds
        expandAll: false // allow having multiple expanded accordions in the menu
    }
});