reCAPTCHA is a spam protection system widely used by websites. If you have a WordPress-based website built with Divi Builder, you can also protect the pages on your website (that contain a form) with it as Divi Builder supports integration with reCAPCTHA. Divi Builder itself has two modules to create a form: the Email Optin module to create an email opt-in form and the Contact Form module to create a contact form. Both modules support reCAPTCHA integration so that you can protect every form you create with Divi Builder.
Divi Builder itself uses reCAPTCHA version 3 in which the protection is based on the interactions made by your visitors with your website. You can read this page to learn more about reCAPTCHA version 3.
How to Add reCAPTCHA in Divi Builder
To add a reCAPTCHA version 3, you need a site key and a secret key. To get ones, visit the reCAPTCHA website and click the Admin Console menu.

Click the plus icon on the upper right side add a new site.

Add a label on the Label section. On the reCAPTCHA type section, select reCAPTCHA v3. Add your domain on the Domains section (hit enter to add a domain). Accept the ToS and click the SUBMIT button.

On the next page, you will get the keys you need. Simply copy them.

The way to add reCAPTCHA to the Email Optin module and the Contact Form module is the same. After adding the module, you can open the Spam Protection block on the settings panel and enable the Use A Spam Protection Service option. Click the ADD button.

Paste the site key and the secret key you have copied to the respective fields and click the SUBMIT button. You can also set the minimum score on the Minimum Score option.

Select an account and close the settings panel by clicking the checklist icon.

Please note that reCAPTCHA version 3 doesn’t require a user action like checking the “I’m not a robot” checkbox so that you won’t see a checkbox like reCAPTCHA version 2.