There are following 3 documents for SSO integration for RHOSP:

• Chapter 2. Federation using Red Hat OpenStack Platform and Red Hat Single Sign-On
• Chapter 3. Federation using Red Hat OpenStack Platform and Active Directory Federation Services
• Chapter 4. Federation using Red Hat OpenStack Platform and other vendors

However, the quality of Chapter 4. Federation using Red Hat OpenStack Platform and other vendors is lesser than other two documents.
The Chapter 4 is missing where enable-federation-openidc.yaml file should be copied from, and missing an instruction to add "-e /home/stack/templates/enable-federation-openidc.yaml" option to "openstack overcloud deploy" command.

This is an document bug ticket in order to request improvements of Chapter 4. Federation using Red Hat OpenStack Platform and other vendors.
The essence of the procedure is the same among all of the documents.
Chapter 4 should have the same quality as Chapter 2 and 3.