Here's an article I posted some time ago on Community describing how to do it in Jira alone: Implementing OKR For Agile Teams in Jira
As @Tansu Akdeniz mentioned, there are also several plugins on the Marketplace that help in creating and tracking OKRs, our OKR for Jira among them. Using a plugin is usually simpler than configuring OKRs in Jira. If you'd like to see a demo of our solution, you can book one here.
Hello Atlassian Community! Feedback from customers like you has helped us shape and improve Jira Software. As Head of Product, Jira Software, I wanted to take this opportunity to share an update on...