Follow the next steps in order to add Captcha to your Wordpress login page (form):
- Open your Wordpress admin Dashboard.
- Navigate to Captcha settings page.
- Find "Enable CAPTCHA" for the "Login Form".
- Save changes.
Note: Captcha will be displayed only in case if you are using the standard Wordpress registration, login and comments form pages.
If you are using custom forms and pages, it is necessary to add changes there, so that captcha could work: