Hi Suresh,
At our company, I do not maintain the OKTA, but I did work with the admin who maintained it. What exactly are you looking to do? Is it for NWBC Client version or web version?
You have to enable SAML 2.0 on the AS ABAP so it acts as the service provider and generate the metadata.xml file and import it on the OKTA IP settings. Not sure where exaclty that is done.
Once that is done, request for a metadata.xml file from OKTA identiry provider and import it into the AS ABAP under SAML2 Config and Trusted procviders. You would also need to provide the OKTA with the NWBC URL that you will be calling so the SAML insertion takes place.
This is the high level setup. However, if you are having specific questions, let me know and I will try to answer.
Thanks
Dhee