reCAPTCHA is a free service that protects your site from spam and abuse. It uses advanced risk analysis techniques to tell humans and bots apart.
You can generate your Captcha key’s on google site: https://www.google.com/recaptcha/intro/invisible.html
And when you are on site, find button “Get reCAPTCHA” after right side.
If you want reCAPTCHA on your site you can easily add this, you must only go to WP-Admin / Settings (WPJB) / Configurate / reCAPTCHA. When you find it, you will see the configuration below.
We can see on this window six options:
Captcha Type: Here you can choose between reCAPTCHA and noCAPTCHA. It is recommended to use noCAPTCHA this is a new version of Google reCAPTCHA, easier for users to fill and much harder for bots to break.
reCaptcha Public Key: Here you must paste earlier created public Key
reCaptcha Private Key: Here you must paste earlier created private Key
Captcha Theme: Here you can change theme your Captcha on light or dark.
Captcha Media: Here you can change Media your Captcha on Audio or Image (it is recommended to use Image).
Enable reCAPTHA for: Here you can select forms which should have captcha enabled.