Importing Password Protected Files
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:
In the example below, you’ll find 3 parts in the link format.
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.