wp menu location

register_nav_menus(array( // Using array to specify more menus if needed
        'header-menu' => __('Header Menu', 'html5blank'), // Main Navigation
        'sidebar-menu' => __('Sidebar Menu', 'html5blank'), // Sidebar Navigation
        'extra-menu' => __('Extra Menu', 'html5blank') // Extra Navigation if needed (duplicate as many as you need!)
    ));