First time - reverse proxy on oracle linux

Hello ,
as I understadn I can use nginx reverse proxy in order to give people access to my local network from the web.
so if my proxy IP is 85.159.4.4 and I want them to be able to enter to devices on 172.16.5/24 -- I can do this
first - is this true?

I setup nginx ,
added a simple link on the /usr/share/nginx/html/index.html
<a href="http://172.16.5.26">Local Device1<a>.</br>.</p>

from the server I have ping and can access to it
but when I connect to the server from the internet - I can't reach it .

what do I need to do in order to make this work?

Thanks ,