Jira integration provides a dashboard widget displaying your important notifications,
a unified search provider to search for issues
and notifications about recent activity related to your assigned issues.
There were newer much development activity in two years existence of this app. "Only" regular maintaining of compatibility with current Nextcloud releases, which would be fine. Number of reported issues is low, but they stopped to be addressed since year 2021, including serious one regarding compatibility with Jira app, to which this app is connecting to.
To conclude - at most somehow maintained, but unable to address changes on service, to which is connecting to