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Search the Custom field name, Click on the “Three“ dots.
Go to contexts & default value.
User will see a page similar to the following example:
Click on the Edit custom field config to configure the Jira expression.
Add the Jira Expression.
Click the Submit button, and the Jira Expression will be added to the configuration.
NOTE: This field is made it as read only so while creating issue it will not appear
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