Using Google's reCaptcha with Web-To-Lead form

Using Google's reCaptcha with Web-To-Lead form

Would anyone be willing to share how to integrate Google's reCaptcha with ZohoCRM's Web-To-Lead form?

I have set up my Web-To-Lead form correctly and the data ends up in the Leads section, as expected.

However, using Google's reCaptcha creates an extra step to the server hosting my website when verifying and this is causing me problems.

The verify.php file I have set up, as per...
https://developers.google.com/recaptcha/docs/php

...has the "// Your code here to handle a successful verification" bit, and I would like the code to send all data that was inputted into the form from my website to ZohoCRM and to redirect the user to a success page as it would normally.

I have tried using the cURL method but couldn't get it to work - is this the right method?
http://www.html-form-guide.com/php-form/php-form-submit.html

Or is there something simpler out there?

The Zoho product development team have "confirmed that we can use the Google's recaptcha while using web forms in Zoho CRM" but they advised me to come here to find the answer.
I've done countless "integrate reCaptcha with ZohoCRM Web-To-Lead" & similar searches on google looking for a way to do this but could not find anything.

If anyone could help on this matter I would really appreciate it.