Microsoft Store login on Windows 10 ?

Windows 10 - local AD joined but NOT Azure joined. Our Users are synced to O365 using Okta.

We have our "Business" Microsoft Store setup and now want to log our users in automatically using their email address from AD.

Having trouble getting SL (8.7.1) to take action on the Window that appears. 

I can get some information on it with WinTool and DotNETWindowFinder but nothing on the actual fields and buttons.

Has anyone had any success with this ?

Cheers

Ian