Hi @Lena Sargsyan ,
with Automation you can't prevent a transition, as the Automation rule would run after the action is done (it works with Triggers, you can't really change this).
However, what you described can be done using a Validator. I would suggest having a look at this documentation page on how to use it : https://support.atlassian.com/jira-cloud-administration/docs/configure-advanced-issue-workflows/
Let me know if this helps,
--Alexis
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.