Users have been unable to login to the desktop Outlook app. They are able to log in online O365, but the same password is not working for the Outlook app. The Outlook app won't go past the username and password screen and does not give an option to enter the 2nd identification step.
How do we get the 2 step identification to work with the desktop Outlook app?
What does the prompt look like? If it's the old-style "security" prompt, you need to make sure that modern authentication is enabled *both* server side and client side. Other than that, clear any stored credentials in cred manager.
Check that modern authentication is enabled for your tenant in Exchange Online.
https://docs.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/enable-or-disable-modern-authentication-in-exchange-online
-Jamie