server {
listen 80;
server_name YOUR.DOMAIN.TLD;

location /screenshots {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://127.0.0.1:YOURSERVERPORT;
    client_max_body_size 100M;
}