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Go to the Atlassian Marketplace page for Add Another.
Buy or evaluate the add-on with a free 30-day trial.
Enter the details on the New evaluation screen and generate a license.
Download the jar file. Now, log in to Jira as an administrator.
Go to the Administration icon and click on it.
Locate Add-ons from the menu and click on it.
Click on Manage add-ons.
Click on and upload the jar file.