Buying and Uploading your License
Buying Elements Copy & Sync from the Atlassian Marketplace
Open the Elements Copy & Sync page on the Atlassian Marketplace.
Click the Buy it now link, this will redirect you to your my.atlassian.com account.
Confirm the order and make the payment.
Once payment is accepted, you will receive an email confirming the license key is available in your my.atlassian.com account.
Upload your license key
Log in as a user with the JIRA System Administrators global permission.
Click the Administration link on the top bar.
Select Add-ons > Atlassian Marketplace > Manage add-ons. The Universal Plugin Manager page will be displayed (see Managing JIRA's Add-ons).
Click the Elements Copy & Sync section to expand it.
Paste your license from your my.atlassian.com account into the License key field and click Update.