I found this to work as a draft only by using the following:
https://WEBSITE/wordpress/xmlrpc.php
I haven’t been able to get images working, but I presume the idea is to have FTP access directly to the WP-content folder and use this to connect.
I note the window help mentions:
“Specify an http or ftp address for Word to publish pictures to. Post beta 2, we plan to have more options in this area.”