Link Issue
The "Link Issue" function will allow you to link existing project tasks with existing JIRA issues. This function is useful when you have tasks that have already been created in JIRA and/or you are trying to repair a project plan that has been corrupted.
To use this function, select one and only one task from your project plan. If you select multiple tasks, you will receive the message below.
The "Link Task To Existing JIRA Issue" dialog will appear. Simply type in the JIRA issue you wish to link to, or use the "Browse JIRA Issues" to select the issue, and press the "Link" button. Your project task will then be linked to the specified JIRA issue.