reCaptcha on CQ5.6.1 Page

Hi

I'm trying to use reCaptcha on one of CQ5.6.1 page. It is working fine on local environment(localhost) but not working on Dev/QA servers. I'm using servlet to validate. My servlet code is

protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response)
            throws ServletException, IOException {

           String secretParameter = "<My Key>";
           String recap = request.getParameter("g-recaptcha-response");
           PrintWriter writer = response.getWriter();
           StringBuilder nsb = new StringBuilder();           

           //Generate URL
           nsb.append("https://www.google.com/recaptcha/api/siteverify?secret=");
           nsb.append(secretParameter);
           nsb.append("&response=");
           nsb.append(recap);
           nsb.append("&remoteip=");
           nsb.append(request.getRemoteAddr());
           
           .
           .
           .
           }

Our Dev\QA domains are registered with the reCaptcha API keys. I found that 'request.getParameter("g-recaptcha-response")' is returning null on QA/Dev environments but on the localhost it is valid.

Any thoughts/help on the reCaptcha not being work on Dev/QA environments?

Thanks in advance for your help.

YRJ