Howto troubleshoot rewrite rule

Hello all,

I am new to haproxy and I have possibly an easy question.
I am trying to setup haproxy as a basic https proxy rewriting http request/response with regular expressions and I am unable to troubleshoot from the logs server side (it does not contain much). How can I see http request/response resulting from my manipulation sent through/behind my haproxy server?

Thanks in advance!