(PHP) Tutorial How to implement simple Google reCAPTCHA on your form

Screenshot :     Required and Included on this source : Bootstrap.css (just for styling)   Register reCAPTCHA from Google open google reCAPTCHA admin page to register a new site     Register your site, choose the type of reCAPTCHA V2. Enter your domain list that using this reCAPTCHA, you can add more than 1 domain here. Then Click Register.   After that. You will get Site key and Secret Key. Site Key is for client side. Secret Key is for server side   Source Code index.php (client side)   submit.php (server side)   nb: replace YOUR_SITE_KEY and YOUR_SECRET_KEY