How to Hide WordPress vertical Thumbnail Slider Admin Menus

function plt_hide_wp_vertical_image_slider_menus() {
	//Hide "Vertical Thumbnail Slider".
	remove_menu_page('vertical_thumbnail_slider');
	//Hide "Vertical Thumbnail Slider → Slider Setting".
	remove_submenu_page('vertical_thumbnail_slider', 'vertical_thumbnail_slider');
	//Hide "Vertical Thumbnail Slider → Manage Images".
	remove_submenu_page('vertical_thumbnail_slider', 'vertical_thumbnail_slider_image_management');
	//Hide "Vertical Thumbnail Slider → Preview Slider".
	remove_submenu_page('vertical_thumbnail_slider', 'vertical_thumbnail_slider_preview');
}

add_action('admin_menu', 'plt_hide_wp_vertical_image_slider_menus', 11);

Where do I put this code?