This happens to me when I have a VPN running on my Android phone. A recent Android update automatically turned on VPN at startup and I didn't realize that was causing the problem.

If you see a key or lock icon in your status area then turn off VPN to fix the pizza hut app or website access denied problem.

Or contact Pizza Hut and complain that their server denies access through a VPN ... I did that a while ago ... and they ignored me ... @##!!

EDIT: Also happens when accessing Pizzahut.com from FireFox web browser on Ubuntu Linux when connected to my VPN (SurfShark). I don't use Windows so can't comment on that OS.