Maybe I am remembering incorrectly, or not understanding this, but doesn't the Jira Cloud integration for Slack (Atlassian's) automatically take a ticket ID and make it a link?
I thought I should be able to write a message in Slack referencing ticket PS-123 and have that show up as a link to the ticket in Jira.
Is this not correct? If it is, I cannot get it to work for some reason...