Nginx als reverse proxy to apache2.2

I have a multiserver ISPConfig installation with a webserver running nginx. and I have an older stand allone mailsystem with a webmail running apache2-2.2.12-1.38.2 on SuSE with self signed certificate not reachable from the internet.
So I like to reach it via a reverse proxy.
I created a website with ISPConfig on the web server running ngnix and secured it with let's encrypt. Works fine so long. Automatic redirection from http to https works too.
But what have i to write to the nginx Directives on the options page to make it a reverse proxy.
Searching now for hours on the net here and anywhere but can not find a real solution.
nginx as proxy before apache is recommended many times but can't find a sample.
need hint or link to solution

Thanks
Rainer,

 

Run this in your browser: site:www.howtoforge.com nginx reverse proxy

 

more than 400 pages of tutorial are not usefull, sorry

 

Sorry can't find that, my you be a little bit more clear, thanks

 

Thanks but what I want is a reverse proxy, no simple redirektion.
so to get near I created a simple hello world website on the apache
and a nginx directive
[location / {
proxy_pass http://my_server.mydomian.tld;
}]
that works
than I modified it instead of my_server ... to my internal mediawiki on the same server
that fails with a 403 as nginx seam to search the pass localy instead of passing it to the backend server, I can not understand why
while accessing the mediawiki direct works fine
Again what I need is a working sample for a reverse proxy with nginx
Thanks for help

 

This is a false statement. Not only there are tutorial, there also threads discussing the same and they do work.

 

OK some things are easier than expected
but still problem with ssl. It works with the simple hello world and a self signed cert but with the webmail app on the older server I get 502 and error like below
[*2 SSL_do_handshake() failed (SSL: error:141A318A:SSL routines:tls_process_ske_dhe:dh key too small) while SSL handshaking]
on apache there are directives to ignore such problems, whats on nginx

Thanks