Oauth with Microsoft authenticator

[lejeczek]

Hi guys.

I'm fiddling with mutt first time and I'm trying to hook 
into Microsoft which I limited by my org - I cannot generate 
any app passwords.
I wondered if it would work with/via "authenticator app" 
where MS generates "Account name" & "Secret key".
As I said I'm fiddling - I use "Account name" for 
'client_id' and here I have a question:
-- when 'mutt_oauth2.py' spits out a URL which I follow, 
then Microsoft landing page tells me "...: Application with 
identifier XYZ was not found..." and what makes me curious 
(even if 'authenticator' way would not work either way) is, 
that @part is missing there in 'identifier', which is in 
original "Account name"
Why would that be would anybody know?

many thanks, L.