get Captcha Token
Gets the website captcha token discovered originally by https://github.com/ahmedgamal17 optimized by https://github.com/justfoolingaround
Parameters
url
the main url, likely the same website you found the key from.
key
used to fill https://www.google.com/recaptcha/api.js?render=....
referer
the referer for the google.com/recaptcha/api.js... request, optional.