I am not sure what OIN is. But I am building an integration for SCIM, following this: Build a SCIM provisioning integration overview | Okta Developer
And I wonder if my application does already meet this criteria or not:
Your Okta integration should use Single Sign-On (SSO) to initiate end-user authentication. Learn how to set up your integration with SSO in our Build a Single Sign-On (SSO) integration guide.
given that I already have implemented this: Sign users in to your SPA using the redirect model | Okta Developer using the OIDC alternative.
I am not sure that your answer made it any more obvious to me.