how do i validate linked issue status before transition change in workflow on cloud

[AC]

Hi, 

where i can set particular check in workflow transition , to check if linked issue is in particular state to proceed in cloud JIRA (it is not subtask it is linked issue)

[Nic Brough -Adaptavist-]

You need validators to do this, but I don't think any of the add-ons available in Cloud allow you to do this.