Hi @Athulya Pillai
Multiple autentication in SharePoint 365 is different from SharePoint Server.
With Multifactor authentication, user authentication is a two-step process and requires the user to prove his or her identity. In addition to passwords, the users are expected to acknowledge a phone call/ text message or mobile app notification to complete the verification process. Multi-Factor Authentication for Office 365 is a form of Azure Multi-factor Authentication, which comes bundled with an Office 365 subscription.
For more information, you could refer to:
https://www.c-sharpcorner.com/article/get-started-with-multi-factor-authentication-in-office-365/
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