Log into your Jira instance as an admin.
Click the admin dropdown and choose Atlassian Marketplace.
Click Find new add-ons from the left-hand side of the page.
Locate Simple Attachments Downloader for Jira via search.
Click Free Trial to begin a new trial or Buy now to purchase a license for Simple Attachments Downloader for Jira
Enter your information and click Generate license when redirected to MyAtlassian.
Click Apply license.