How to allow only incoming HTTP/HTTPs traffic from WAN interface?

[ogzy]

I am trying to design a reverse proxy structure that will direct traffic to some web servers behind. At the entry point, i want to allow just HTTP or HTTPs traffic. I want to do this by using DPI. I couldn't figured out how to do it via PfSense. L7 filtering only lets blocking, firewall rules depends ports. I need to define  L7 filtering rule that will only allow HTTP traffic but for the traffic coming to WAN interface.

How can i do it?