Azure AD B2C - Sign out a user from all sessions

I might be late. But if that helps. A.c to docs

When you redirect the user to the Azure AD B2C sign-out endpoint (for both OAuth2 and SAML protocols), Azure AD B2C clears the user's session from the browser. However, the user might still be signed in to other applications that use Azure AD B2C for authentication. To enable those applications to sign the user out simultaneously, Azure AD B2C sends an HTTP GET request to the registered LogoutUrl of all the applications that the user is currently signed in to.

Applications must respond to this request by clearing any session that identifies the user and returning a 200 response. If you want to support single sign-out in your application, you must implement a LogoutUrl in your application's code.

This is called single sign out . Please refer to https://docs.microsoft.com/en-us/azure/active-directory-b2c/session-overview#single-sign-out

According the description on Azure Document:

While directing the user to the end_session_endpoint will clear some of the user's single sign-on state with Azure AD B2C, it will not sign the user out of the user's social identity provider (IDP) session. If the user selects the same IDP during a subsequent sign-in, they will be reauthenticated, without entering their credentials. If a user wants to sign out of your B2C application, it does not necessarily mean they want to sign out of their Facebook account entirely. However, in the case of local accounts, the user's session will be ended properly.

So you can directly use the end_session_endpoint. You can find it in the metadata document for the b2c_1_sign_in policy endpoint, e.g.:

https://login.microsoftonline.com/fabrikamb2c.onmicrosoft.com/v2.0/.well-known/openid-configuration?p=b2c_1_sign_in

You can refer to Azure Active Directory B2C: Web sign-in with OpenID Connect for more info.

Any further concern, please feel free to let me know.