Whew, writing an entire post about OneClick is going to be a challenge!
In your admin menu, choosing 'Import from JIRA' opens a straightforward form.
Fill in the connection details, and YouTrack will discover what permissions you have in each of the JIRA projects.
Give me power
In case you don't have certain permissions in your JIRA, you will experience the following kinds of frustration (since some of your data may not be imported):
Without a Jira System Administrator, Jira Administrator or Administer projects role, no JIRA group members and no role actors will be imported. Im