While the app is indexing builds, you may see the following message on the TeamCity tab.
This process may take a while on large instances. Also, please see here.
Once the initial indexation has completed, you will see all builds that pertain to the current project on the TeamCity tab.
If no relevant builds are found, you will see the message No associated builds are found. From the current moment, the app will update the build list in Jira every 2 minutes.
If you see the message that no builds are available, please see this page to identify its cause.