We do support using third party site as a safe page or money page.

Third party site can be any site on the internet, for example, a WordPress site or blogger site or sites like Facebook, Youtube etc...

You will still need a hosting and a domain, to upload the PHP file.

If you want to use a third party site as money page, please use PHP upload: https://docs.fraudfilter.io/kb/php-upload/

If you want to use a third party site as safe page, please use PHP upload: https://docs.fraudfilter.io/kb/php-upload/

P.S. You can use a third party site as a safe website but you can't upload any code on the websites which you do not own.