Authenticator app requires me to use authenticator app to log in

so i deleted and reinstalled the app

This might have been fatal.

You can restore from backup (assuming there was one) but make sure no accounts have been added to the newly install app. Then sign on with recovery account to do the restore.

You can recover your account credentials from your cloud account, but you must first make sure that the account you're recovering doesn't exist in the Microsoft Authenticator app. For example, if you're recovering your personal Microsoft account, you must make sure you don't have a personal Microsoft account already set up in the authenticator app. This check is important so we can be sure we're not overwriting or erasing an existing account by mistake.
https://support.microsoft.com/en-us/account-billing/back-up-and-recover-account-credentials-in-the-authenticator-app-bb939936-7a8d-4e88-bc43-49bc1a700a40

--please don't forget to upvote and Accept as answer if the reply is helpful--

I just want to throw out there (since I found this while searching, and I wouldn't want to leave a DenverCoder situation) that the user may not realize their phone is not connected to the account properly, because the MS Auth app doesn't look particularly different in some cases.

I had a user that migrated to a new phone, and the MS Authenticator App picked up on the Office 365 account from the other apps on the phone, and the email showed up as a "Connected Account" when we tapped into the account but would not receive notifications or provide One-Time Passcodes for the account, even though it was listed.

Outlook Mobile was prompting to "switch to authenticator" and then once we were IN authenticator it offered the same prompt to "Switch to authenticator" again, endlessly. Presumably because it was not finding the matching account in the app.

After we re-setup their MS Authenticator, we got more options shown when we tapped into the account, and it showed options including

• "Notifications Enabled"
• One-Time password
• Change Password
• Update Security info
• Review Recent activity

or slightly different language if they are enabled for passwordless login

It sounds like you're caught in a frustrating loop. You may need to contact your email provider's support for account recovery options or see if there's a backup method for authentication, like SMS or security questions.

More Details:

AD administrator completely sure that he didn't set authenticator with active directory account.

but now he logged out and when he try to login its keep asking to enter code.

now administrator unable to login in my azure portal.

I have had the same problem. I could finally solve it because the admin was able to add an additional authentication method (SMS to my phone). I could then switch to "another method" when I was required to authenticate, and pick SMS.