Forward all domain requests from one server to another?

Question

Nginx

There is a domain that is forwarded to a server with a direct IP.
There is a second server that does not have a real IP, but is connected to the same network, or free dyndns is connected.
The first server has nginx, and it has two domains.
Tell me how you can completely forward the second domain for all requests to another server?

Answer 1

On the first server, in the settings of the second domain that is connected there, do:
location / {
proxy_pass http://ip_where_the_second_domain:port_probably_80;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
}