/etc/nginx/proxy.conf

proxy_pass http://localhost:81;
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_connect_timeout 90;
proxy_send_timeout 90;
proxy_read_timeout 90;
client_max_body_size 10m;
client_body_buffer_size 128k;
proxy_buffer_size 4k;
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;