Quickad - ­Classified Ads CMS PHP Script

How I can setup Google reCaptcha?

You have to get a site key from https://www.google.com/recaptcha/

Once you got the site_key, you can add it in Admin panel > Settings > Google reCAPTCHA > reCaptcha key. and add reCAPTCHA Public Key and reCAPTCHA Private Key:.