This is string present in Woocommerce plugin files. You can find it in these files: wp-content\plugins\woocommerce\i18n\languages\woocommerce.pot
wp-content\plugins\woocommerce\includes\wc-template-functions.php
We recommend you to use the .pot file to translate strings or changes them. Save a copy of the edited file to retrieve in case of future plugin update.
