Paulie proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Forwarded-Protocol $scheme;
proxy_set_header X-Forwarded-Port $server_port;
All these settings are automatically set by the reverse-proxy feature in Abyss Web Server.
Paulie proxy_set_header Host $host;
This is a special setting that requires checking Preserve Host Header in Advanced Parameters in the reverse-proxy rule.
If these settings do not help, a description of the full use case will probably help us understand the context and suggest the most adequate equivalent settings.