1. Open Google reCAPTCHA and create a new site.
2. Fill in the required details, then click Submit.
3. Copy the Site Key and Secret Key.
4. In Marketo, click Admin.
5. Under Integration, click CAPTCHA.
6. Click Edit.
7. Select the CAPTCHA type, then paste the Secret Key and Site Key.
8. Click Save.
9. Open your form and click Edit Form.
10. Go to Form Settings > Settings.
11. Set CAPTCHA to Enabled.
12. Click Finish, then click Approve and Close.