HAProxy internal network redirection

Hello everyone,
I am new to HAProxy so I need help, I wanted to create a list of blocked websites where a user on the local network, if attempting to access any of these sites, will be redirected to a local page. I tried probably almost everything I found on the internet and nothing succeded.
Is it possible on haproxy?
I tried load balancing and it works like a charm, but I need a little bit different scenario now as you can see.
If it’s relevant, I have haproxy version 2.16.12 running on Debian 12.

Thanks in advance to anyone who have any idea.