In this tutorial, We’ll guide you How To Display reCapcha in K2 Comment.

On  https://www.google.com/recaptcha/intro/index.html site 

• Firstly, you have to create a Recaptcha account here: https://www.google.com/recaptcha/intro/index.html
• Navigate to “Get reCAPTCHA” button >> and click “Sign Up Now” >> enter your “Domain” name and click “CREATE” a key >> Copy (Public Key and then you will copy the Private Key)

In the Admin Panel, go to:

• Component -> K2 -> Parameters -> Comments-> Active reCaptcha -> Yes.
• Go to Component -> K2 -> Parameters -> Advanced -> Anti-spam.
• Paste the two Key that you have from Google. (Public and Private Key) and Save

-> Refresh you site and you got it

Feel free to check the detailed VIDEO TUTORIAL