Navigate to your project, then go to [Project] » Settings » Ticketing Integrations » JIRA.

JIRA

Enter your JIRA account URL, username, password, and project key, then click Save.

Go to Errors or JSErrors menu from your project dashboard,click on an error you want to place in your issue tracker. Look for JIRA menu below the error message in the top-left and clicking it will give you an option to create JIRA issue, or link to existing issue in your project.