[Includes] Adding an Extension
Log into your Jira Server instance as an Administrator.
Click on the Administration icon in the upper right corner.
Select Issues.
In the left-hand panel, click Workflows.
Click Edit for the workflow to be edited.
Edit the Transition:
When viewing the Workflow in Diagram view, select the Transition and click the link for the extension type to be added (e.g. Post-function). Click the Add link at the top of the list of existing extensions.
When viewing the Workflow in Text view, click the name of the Transition then select the tab for the extension type to be added (e.g. Conditions). Click the Add link at the top of the list of existing extensions.
Select the extension from the available list and click Add.
Configure the extension as needed.