Hi,
Without some type of example link it is hard to provide any more ideas. It’s rare that you wouldn’t be able to pull the request if you can get it on the browser. It is usually a matter of headers like content-type, user-agent, etc., something the script is expecting that is default via a browser call.
I usually use Postman to figure these things out, or if the cgi script you are using is open-source I could put it on my server and test, but beyond that I’m out of options for you.
-dev