How to Hide WP Charts and Graphs Admin Menus

function plt_hide_wp_charts_and_graphs_menus() {
	//Hide the "Charts and Graphs" menu.
	remove_menu_page('pantherius_wp_charts');
	//Hide the "Charts and Graphs → Generate Chart" menu.
	remove_submenu_page('pantherius_wp_charts', 'pantherius_wp_charts');
	//Hide the "Charts and Graphs → Settings" menu.
	remove_submenu_page('pantherius_wp_charts', 'pantherius_wp_charts_settings');
}

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

Where do I put this code?