Yes, you can add multiple accounts to your Microsoft authenticator app.
you can ask followup questions here in dedicated forum for Microsoft authenticator app
https://social.technet.microsoft.com/Forums/en-US/home?forum=MicrosoftAuthenticatorApp
--please don't forget to Accept as answer if the reply is helpful--
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Regards, Dave Patrick ....
Microsoft Certified Professional
Microsoft MVP [Windows Server] Datacenter Management
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