When registering an application in Azure Active Directory (Azure AD) for authentication, one of the key configuration items is the redirect URI. According to Microsoft Identity Platform Documentation and the SC-
300 official study guide, the redirect URI (or reply URL) specifies where Azure AD should send the authorization code or access token after a successful sign-in.
The guide explains:
"During app registration, Azure AD requires a redirect URI to identify where authentication responses are sent. For web apps, this must be a valid HTTPS endpoint where your app listens for responses from the Azure AD authorization endpoint." In contrast:
* The executable name, bundle ID, and package name are identifiers relevant to desktop or mobile app packaging and are not part of Azure AD web app registration configuration.
* Only the redirect URI ensures proper return of authentication tokens in OAuth 2.0 and OpenID Connect flows.
Thus, when registering a .NET web app (App1) for Azure AD authentication, you must configure the redirect URI to handle token responses securely.