Reverse proxy first time setup

Hello
I want to setup a reverse proxy "before" my local netwrok
I have a public IP for the nginx server which is 85.123.144.5
the local IP is 10.29.20.22
from the nginx server I can go to 172.16.x.x and also 10.29.x.x (all ports are open )

in the nginx I put a simple "FirstPage.html" that have links to all my devices (172.16.254.200 , 172.16.41.4 10.129.20.21 and so on)
when I press the link it get stuck and get error connection to wanted ip

what I need to do to make this work?


this is what I have (after trying all kind of things) - please feel free to fix and teach me

server {
listen 80 default_server;
listen [::]:80 default_server;
server_name _;
root /usr/share/nginx/html;

# Load configuration files for the default server block.
include /etc/nginx/default.d/*.conf;
location ~ ^/FirstPage.html/(.*)$ {
#proxy_set_header Host $http_host$request_uri;
proxy_pass http://x.x.x.x/$1;

#proxy_read_timeout 120s;
#access_log on;


}
{

can some one guide me and explain to me what I need to do ?
* I know this not good , but this is the last test I made - I have try all kind of setting *
Thanks ,