You can watch the video or follow the steps.
Visit the Atlassian Marketplace and search for JFrog.
You should see the JFrog Platform: Artifactory App for Jira. Click on the icon on the top-right and hit the Get it now button.
The JFrog app installs into your JIRA instance.
Once installed, a pop-up appears on the top-right of your screen. Click on Get started.