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Associating using a check-in comment
Associating a TFS / Azure DevOps (formerly VSTS) check-in with a Jira issue is very simple and straightforward. The only thing that you have to do is type an issue key as a part of your TFS / Azure DevOps (formerly VSTS) check-in / Git commit message, as shown below. The key can be anywhere in the comment.
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It is also possible to associate a check-in with a Jira issue by typing an issue key as a part of any check-in note associated with the check-in. Name of the check-in note is not important - all notes are scanned, but it may be a good idea to name the check-in note accordingly and perhaps even make it mandatory in order to enforce a Jira integration policy.
Associating using TFS / Azure DevOps (formerly VSTS) Work Item
If you have properly set up your TFS4JIRA Synchronizer application to perform TFS / Azure DevOps (formerly VSTS) to-and-from Jira issues synchronization and (in case of Jira Cloud environment) exposed it to web requests from the Internet (see Settings for Jira JIRA Cloud), associating check-ins with Jira issues is even easier - actually it is fully automatic. All you need to do is associate your check-in with a TFS / Azure DevOps (formerly VSTS) work item and the Synchronizer will take care of the rest - it will find the work item's matching issue and when you open that issue it will display the change-set.
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