Sign in With Microsoft
Tuple gives users the ability to sign up and sign in with Microsoft. Team owners have the ability to select Google, Microsoft, or SAML SSO as a required authentication provider; if none is selected, users can choose how they want to authenticate. The setting can be changed in the team settings tab:

FAQs
What happens if I attempt to transfer a user into a team where they don't meet the auth requirements (i.e. if a team requires Microsoft auth, but the user in question hasn't used it)?
The transfer request will be blocked
If a team has auto-join functionality enabled, what will happen if a user signs up but doesn't meet the auth requirements for the team?
The user will be prevented from joining the team.
When a team makes Microsoft auth required, what happens to users who had previously been using email and password?
Existing users are shown an error message when attempting to log in which prompts them to sign in with Microsoft. Users are not logged out from existing sessions.
When a team switches from Microsoft auth to a different required auth provider, what happens to users who had previously been using Microsoft auth?
Existing users are shown an error message which prompts them to sign in with an email / password. If they don’t have a password set, they’ll need to go through the reset password flow. Again - users are not logged out from existing sessions.
If a user changes the email address associated with a Tuple account, will that automatically update or invalidate the linkage with the associated Microsoft account?
No. Users who change their email address in Tuple do not automatically have their link to their Google account broken. For example, someone could sign up via Microsoft using the email address first@tuple.app , then change the address associated with their Tuple account to second@tuple.app . In this case, they would still be able to sign in via the Microsoft account first@tuple.app . If a different user actually had the Microsoft account second@tuple.app , they wouldn't be able to use Microsoft auth until the first user switched their email address back to first@tuple.app (or to something else entirely).