I am trying these days to setup a reverse proxy on my pfSense running in a virtual machine.
pfSense is working great, port forwarding is working great for over one year now.

I tried a few tutorial found online but none of them are really working as they should. Like, they do not resolve anything.

Could anybody help me with frontend page editing on HAProxy for the reverse to work? Or with Squid reverse proxy setup if that sounds easier?

What I know:
My external domain (dynamic ip): "example.com" - this is already working, I can access redirected ports on this address.
Internal servers:
server1: "internal ip1":"port number1"
server2 "internal ip1":"port number2"/web
server3: "internal ip2":"port number3"

What I want:
Redirect "server1.example.com" to "internal ip1":"port number1"
Redirect "server2.example.com" to "internal ip1":"port number2"/web
Redirect "server3.example.com" to "internal ip2":"port number3"

I am not using SSL. I just want simple redirects from port 80 to different servers/ports on the internal network.

I followed these tutorials until now:
https://travellingtechguy.eu/reverse-proxy-with-pfsense-and-squid/
https://www.reddit.com/r/homelab/comments/2vyiiy/til_reverse_proxy_via_squid_in_pfsense/
Others too.

The problem is that none of these have all the details included. As I was not able to achieve the end result wanted.

I did set the rule to allow port 80 traffic in the firewall.
I setup pfsense admin page on another port (other than 80).

In HAproxy I configure backend and frontend, but only the direct "example.com" will redirect to its routing rule. All other "server*.example.com" will fail.
Thanks in advance.