The configuration reverse proxies the machine URL plus the /drop/ subpath to the pairdrop daemon listening on the same machine on port 3001

        redir /drop /drop/
        handle_path /drop/* {
                reverse_proxy 127.0.0.1:3001 {
                        header_up Host {host}
                        header_up X-Real-IP {remote}
                        header_up X-Forwarded-Host {hostport}
                        header_up X-Forwarded-For {remote}
                        header_up X-Forwarded-Proto {scheme}
                }
        }