By default, usernames and passwords are available as sign-in methods. You can also use one-time passcodes or social accounts from Google, Facebook, Apple, or a custom OIDC federation.
You can add a Microsoft account as an OpenID Connect identity provider; however, there is no direct option to use a Microsoft account as a sign-in method.
By default, the Microsoft banner logo will appear on the sign-in page. Yes, you can customize your own banner logo instead of the Microsoft logo by using the company branding feature in Entra External ID. To do this, sign in to your tenant, use the search bar to find Company Branding, then click Edit. Upload your image in the Banner Logo field and click Save.
For more information, visit: https://learn.microsoft.com/en-us/entra/external-id/customers/how-to-customize-branding-customers
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