nginx reverse proxy for ssh reverse tunnel?

[jalil1408]

* 192.168.1.100 (reverse proxy and ssh tunnel server) : centos 8 + sshd 8 +
nginx 1.14.1 + firewalld disabled
    * 192.168.1.101 (local web server) : windows 10 + web App (port 80)
exposed to remote access with SSH reverse tunnel (port 6033)
    * 192.168.1.102 (remote machine) : Ubuntu + curl
        curl http://192.168.1.100:6033/api/Users ==> works well
        curl http://192.168.1.100/tunnel/api/Users ==> "the page you are
looking for is temporarily unavailable" !!!

tried with this [/etc/nginx/nginx.conf]

...
http {
    ...
    server {
        ...
        location /tunnel/ {
            proxy_pass http://127.0.0.1:6033;
        }
    }
}

then with this [/etc/nginx/nginx.conf]

...
http {
    ...
    
    upstream tunnel {
        server 127.0.0.1:6033;
    }
    
    server {
        ...
        location /tunnel/ {
            proxy_pass http://tunnel;
        }
    }
}

how to make a working nginx configuration that forward server port 80 to the
ssh tunnel port 6033?

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,288756,288756#msg-288756