HAProxy rewrite URL

[meyerf]

Hello OPNsense Community

I have a question regarding HAProxy.

This is what I want to do with HAProxy:

Forwarding https://xyz.com/a -> https://xyz.com/a/b.html

I was already able to set up forwarding successfully.
But now it would be nice if the URL in the browser doesn't change and in the example from above is https://xyz.com/a.

Do you know a way to set this up with HAProxy?

Thanks for helping

Cheers,
Flavio