Unless you tried their free hosting, Byet, iFastNet’s premium hosting system is entirely different from that of free hosting and does not have the same restrictions set in place.
Generally, when using a service outside of the functionality that is supported, you can operate on a trial and error model, but be aware that if the “website hosting only” rule starts being more strictly enforced, you could find yourself suspended, and that if you run into the limitations, they cannot be lifted, so you’ll have to upgrade to premium hosting or look for a different provider.
If you have a custom domain, you could look into whether integrating Cloudflare can allow you to use your website as you want to: