Default Assignee For a field value when we move from one transition to another

[Akshith Kumar]

How to write a automation rule When we select some field value and when we move from one transition to another the default assignee should be changed.

[Jack Brickey]

Are you using Automation for Jira or something else? If A4J it would look something like this..,

Trigger – issue transitioned

Condition –issue field condition to check the value of the field you're interested in

Action - assign issue