Hi, my name is Fabian from Okta Customer Support and I'll be helping out on this one. We don't have anything on the roadmap for JIRA Data Center yet so you could raise this as a feature request on the support page if someone didn't do it already.
You can suggest this on the Okta Community portal by using the 'Feedback' option at the bottom of the Okta admin console. Features suggested in our community are reviewed and can be voted and commented on by other members of the community, therefore making it much easier for the engineering team to understand the priorities that you have for feature requests. From there, the PM team will review the top 30 most voted upon ideas each month and provide feedback/roadmap status on these via the forum.
Without provisioning you can't have users provisioned from OKTA to JIRA so you will need to manully create the users in JIRA.