Adding Re Captcha to your site

I want to add Re Captcha to my wordpress site and i'm using google recaptha for it : https://www.google.com/recaptcha/intro/

And the plugin i'm using on wordpress is Better WordPress reCAPTCHA.

adding the keys which google recaptcha generates to that plugin is an easy step but how to these 2 steps 1. client side integration 2. server side integration

I'm not able to find the html template it is talking about.

step 1. Client side integration Paste this snippet before the closing tag on your HTML template:

Paste this snippet at the end of the where you want the reCAPTCHA widget to appear:

How to do this ?

And secondly how to do the second step that is server side integration ?

Please tell me what should i do ? thanks in advance.