If you do not want to use the app on your mobile for authentication, you can also add an add-on to your browser. Below is a guide for Chrome. The setup for Firefox or Edge is about the same.
Go to this website, or search for Authenticator at Google and download the addon from «authenticator.cc»
Select: Add to Chrome
Select "expansions" in the top right corner of Chrome
Go to your Microsoft 365 account to configure Authenticator as a method for two-step authentication: https://myaccount.microsoft.com/ Log in if you are not already logged in.
Select Security info
Select Add method
Select Autenticator-app from the drowp down meny and then Add
Select "I want to use a different authenticator app" and then Next (A QR-code will appear on the screen)
Open the authentication addon from the browser
Click the symbol for scanning QR-code in the top right corner to add an account
Can the QR-code by drawing a square around it. Then select Next
Open the authentication addon again
Click the number and give permission to copy data. Move the mouse cursor to the other image and paste the number in the field Enter code. Then select Next.
The authentication addon is now configured to work with Microsoft 365.
Select "Set default sign-in method".
Select "Authenticator app or hardware token - code". Then Confirm.
Why two-step authentication?
Many users are exposed to frauds where they give away their passwords. This can happen by leaks from websites you have visited, weak passwords or e.g. phishing attacks.
If the username and password becomes known to unauthorized persons, they will be able to log in as you. They will have access to all the information that you have access to. For example documents in OneDrive or email correspondence. If the wrong people can access your account, it can have major damage! By adopting two-step authentication, you protect your data.
Email / calendar on mobile / tablet
If you use e-mail and calendar on mobile / tablet, you must use the Outlook-app for the security mechanisms to work on these devices.