Site is fine via browser but 403 accessed programmatically

General
3

I regret that I do not know what any of those terms mean, nor do I have any idea how their Cloudflare settings are configured. The site belongs to the customer of the web application I maintain, and I need to access a page of that site with my C# code. All I get is 403 and I am hoping to know the best way to ask the client’s site admin when I finally contact him/her. What’s killing me is that requests from any browser on any client machine get a valid response; I’ve traced the headers and they are only sending four headers:

  GET /offices/ctbto_vie HTTP/1.0
  Host: unjobs.org
  Accept: text/html, text/plain, text/css, text/sgml, */*;q=0.01
  Accept-Language: en
  User-Agent: Lynx/2.8.8dev.15 libwww-FM/2.14 SSL-MM/1.4.1 OpenSSL/1.0.1e-fips

which I’ve emulated and it still fails, so I’m at a loss.

Thanks for your time.