Divi Module Pro
The process of adding the Divi module in the Divi Editor is pretty similar to how you'd add a regular Divi module. You'd first search for the Login With AJAX block, which you could do simply by searching for login:
When you add the module, you will see the login form by default. All the options available to you are covered in the login form documentation page.
Additionally to these options, you will see an extra option called
Guest Preview Mode, as per the screenshot below. By toggling this option on/off, you will see the form view whilst logged in or logged out.