Changing between multiple Microsoft Teams accounts within the app or browser
Could you please confirm whether Microsoft Authenticator is installed on your phone and that you've signed in to it with your work account?
If Authenticator is already set up, please try signing in to Microsoft Teams again. During the sign-in process, you should receive a verification prompt or code in the Microsoft Authenticator app. Approve the sign-in request or enter the displayed code when prompted.
If you do not receive the Authenticator prompt or code, please let me know what error message or error code you see in Teams.