Introducing reCAPTCHA v3
reCAPTCHA v3 helps you detect abusive traffic on your website without user interaction. Instead of showing a CAPTCHA challenge, reCAPTCHA v3 returns a score so you can choose the most appropriate action for your website.
reCAPTCHA protect your website from fraud, spam and etc when user input comments or fill form on your website. reCAPTCHA v3 is the newest version 2018. Some of details infromation about reCAPTCHA

Here’s some step to create site key and secret key to making reCAPTCHA
First step you should download Recaptcha pluginn on your website
go to SAP Portal
Go to help SAP PORTAL and click agree

after click AGREE button, you will be redirecting on Google reCAPTCHA view interface, see abov

This is example how to fill reCAPTCHA form.
in a domain form fill only the domain, please don’t use http or https it will be not working and failed.
Label for notice name, choose reCAPTCHA v3, input your domain name without https or http, input email. tick accept agreement and OK
And here’s site key and secret key only for your website, copy and paste into your website
here’s interface website