Procédure
The purpose of a captcha is to differentiate a genuine human user from a malicious computer programme used by spammers and other hackers.
This tutorial shows you how to install a captcha on your Joomla site.
To install a cpatcha in your Joomla site:

Then click on CAPTCHA - ReCAPTCHA

To make the reCAPTCHA work, you need to enter the site key and the secret key, which you can retrieve from your Google account by following this link: https://www.google.com/recaptcha/intro/v3.html

Then click on the Status drop-down list to activate the plugin on your site, then on Activated.

Save the changes by pressing the Save or Save & Close button.

You are now able to insert a captcha on your Joomla form. This will identify whether it's a robot or a real person and will prevent spam being sent via your Joomla hosting.
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