You are implementing a website that will allow users to log in using their existing...

To configure your website and SAP Customer Data Cloud for allowing users to log in using their existing company credentials via an OpenID Connect (OIDC) flow, you should set:

SAP Customer Data Cloud as the Relying Party (RP), and the website as the Identity Provider (IdP).

This configuration allows the website to authenticate users and then pass the authentication information to SAP Customer Data Cloud for further processing.

References

SAP Customer Data Cloud OIDC Configuration Documentation