Can't add MS 365 Exchange acct, constant login dialog

What might be wrong when trying to add a MS 365 mail account.
Looks like account is added under Accounts, but this dialog persists. Correct credentials entered doesn’t solve. I have used the same email address as user name also.
Using version: 9.1.2109 (9967b93)

emClient_Addfail

This is because your email provider no longer accepts username/password logins to their server.

Go to Menu > Accounts and remove the account.

Then click on Add Account and enter the email address in the Automatic Setup.
You will be passed to your web browser to authenticate the account, then back to eM Client where the account will have been setup with oAuth (passwordless).

Thanks Gary!
That solved it.