Set Password in the Block Editor
1. Click on "Document" in the sidebar
2. Click "Status & Visibility" to expand the visiblity options
3. Click on the current value of the "Visibility" option (e.g. "Public") to open the "Post Visibility" popup
4. Set "Post Visibility" to "Password Protected"
5. Enter your desired password in the field marked "Use a Secure Password". The Visibility setting will update to "Password Protected" and clicking elsewhere in the post will close the popup
Set Password in the Classic Editor
* You are using an older version of WordPress
* You are using the Classic Editor plugin
* You have enabled the classic editor or the "Latest Divi Builder Experience" from within the Divi Theme Options (under "Builder > Advanced")
To set the password in the classic editor:
1. Locate the "Publish" box in the classic editor screen sidebar
2. Click on the "Edit" link next to the "Visibility" option
3. Set the "Visibility" to "Password protected"
4. Enter your desired password in the "Password:" box
5. Click "OK"
Setting the Password in the Divi Visual Builder
1. Click on the "Edit Post" or "Edit Page" link in the admin bar at the top of the visual builder screen.
2. Set the password following the instructions for the Block Editor or Classic Editor above, as applicable
3. Save your changes
4. Return to the visual editor to complete editing of your post / page
Accessing a Password-protected Page / Post
Styling the Password Entry Form
Divi doesn't offer much in the way of options for changing the look of the password entry form or password protected page / post.
To address this, I created the Divi Password Box module, which replaces the default Divi password entry form with a highly-configurable module, and enables editing of the entire password protected page / post using the Divi Builder.