WP All Import can import XML & CSV files that are protected by HTTP Authentication.

In Step 1, choose the Download  From URL option.

Then enter the URL to your file like so:

http://username:[email protected]

In the example below, you’ll find 3 parts in the link format.

http://louis:[email protected]/soflyy/feed.xml

Username: louis
Password: znxah&jfja_
Link To File: some-site.com/soflyy/feed.xml

To find out if your password-protected file is using HTTP authentication, just enter the URL to it with the username and password specified in the above format into your browser.

If the file begins to show or download, it is using HTTP Authentication.