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For server version, you can extend your app trial up to 5 2 times, so the maximum duration of Server version trial is limited to 6 3 months.
Go to https://my.atlassian.com/ and log in (you may have to ask your Atlassian Billing contact to do this for you).
Find ActivityTimeline: Plan & Track Resources: Trial in the list of licenses and click on expand icon.
Click New Trial license
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