How to Hide the "Solid Security Log Cleaner" Admin Menu

function plt_hide_log_cleaner_for_ithemes_security_menus() {
	//Hide the "Tools → Solid Security Log Cleaner" menu.
	remove_submenu_page('tools.php', 'log-cleaner-for-solid-security');
}

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

Where do I put this code?