Azure Active Directory B2C (Azure AD B2C), an identity store, is an identity management service that enables custom control of how your customers sign up, sign in, and manage their profiles when using your iOS, Android, .NET, single-page (SPA), and other applications.
You can set up sign-up and sign-in with a Facebook/Google account using Azure Active Directory B2C.
Branding
Branding and customizing the user interface that Azure Active Directory B2C (Azure AD B2C) displays to your customers helps provide a seamless user experience in your application. These experiences include signing up, signing in, profile editing, and password resetting. This article introduces the methods of user interface (UI) customization.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory-b2c/
https://docs.microsoft.com/en-us/azure/active-directory-b2c/identity-provider- facebook?pivots=b2c-user-flow
https://docs.microsoft.com/en-us/azure/active-directory-b2c/customize-ui-with-html?pivots=b2c- user-flow