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Unfortunately, JIRA does not have the functionality to automatically create a story when an Epic is transitioned, however, you can achieve it using some plugins.
My recommendation is to use Automation for JIRA and configure a rule like this:
Please, let me know if this is the feature you are looking for.
To see this feature in action check out our recent dependencies demo here: https://www.youtube.com/watch?v=eQu5VsUqyZA Keeping on top of your dependencies is a key part of ensuring project success....
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