How to Hide A2 Optimized WP Admin Menus

function plt_hide_a2_optimized_wp_menus() {
	//Hide "A2 Optimized".
	remove_menu_page('a2-optimized');
	//Hide "A2 Optimized → Page Load Speed Score".
	remove_submenu_page('a2-optimized', 'admin.php?page=a2-optimized');
	//Hide "A2 Optimized → Website and Server Performance".
	remove_submenu_page('a2-optimized', 'admin.php?page=a2-optimized&a2_page=server_performance');
	//Hide "A2 Optimized → Optimization".
	remove_submenu_page('a2-optimized', 'admin.php?page=a2-optimized&a2_page=optimizations');
}

add_action('admin_menu', 'plt_hide_a2_optimized_wp_menus', 11);

Where do I put this code?