Older versions of add-ons are available on https://marketplace.atlassian.com
JIRA Agile in particular can be found here.
Download the most recent available version for your version of JIRA and use the Installing by file upload method to get it up and running on your instance.
This should cover all 3 of your questions
Hey Community mates! Claire here from the Software Product Marketing team. We all know software development changes rapidly, and it's often tough to keep up. But from our research, we've found the h...
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