Perform As User

When choosing a user account to run a post function, the account specified must have the appropriate permissions to perform the actions of the post function, for example, creating an issue or adding a comment. You can specify a different user account that has the necessary permissions to act as a technical (impersonation), with broad permissions, but not used to log in to a Jira account as an individual. 

If you don't specify a user here, the transition on the related issue is performed as the same user who triggered this post function on the origin issue, by default. Therefore that user must have the necessary permissions on the related issue.

In combination with the User is in Any Users condition, you can hide a transition from all users other than the selected Perform As User.