VB App, CPQ SSO enabled integrating with a Third Party App

Content

We have build a VB application which is SSO enabled with Oracle CPQ.
Within this application we have embedded an iframe to a Third Party Application.
From the Third Party Application we invoke an Oracle CPQ Webservice and it should open the CPQ page.
But we encounter the login page for the CPQ, typically we should be able to proceed to the CPQ page.

Question : How do we make sure the Third Party Application is able to access the CPQ page which is Oracle SSO enabled.

Can we set up a third party application inside the IDCS so that SSO can be established across the application which are on the same IDCS.