This article provides the steps to configure an Identity Provider (IdP)-initiated Security Assertion Markup Language (SAML) login from Azure to Auth0, which acts as the Service Provider (SP).

• Azure
• Auth0
• SAML
• IdP-Initiated

1. Create a SAML connection with Auth0 as the SP and Azure as the IdP. Refer to Setting up Azure AD as SAML enterprise connection.
2. Enable the IdP-initiated SSO setting in the SAML connection settings.
3. (Optional) To test the flow from an application that communicates with Auth0 using the OpenID Connect (OIDC) protocol, configure the application by following the guide, Configure IdP-Initiated SAML Sign-on to OIDC Apps.
4. In the Azure Portal, choose Microsoft Entra ID > Enterprise Applications > Your SAML Application > Single sign-on.
5. Ensure that the Sign on URL field under Basic SAML Configuration is empty. This configuration ensures that Azure performs an IdP-initiated flow, which authenticates the Azure user and then posts a SAML response to /login/callback. If a Sign on URL is configured, Azure redirects to that URL to start an SP-initiated flow.
     
6. Navigate to Test single sign-on with SAML IdP and select the Test button.