How to Hide the "User Spam Remover" Admin Menu

function plt_hide_user_spam_remover_menus() {
	//Hide the "Users → User Spam Remover" menu.
	remove_submenu_page('users.php', 'user_spam_remover');
}

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

Where do I put this code?