CXone Reporting v2 API returns empty for real-time queue stats

I’m trying to pull real-time queue statistics via the CXone Reporting v2 API, but the response is always empty. The request looks like this: GET /api/v2/analytics/reporting/queues/realtime?interval=2024-05-01T00:00:00Z/2024-05-01T01:00:00Z. The status code is 200, but the data array is null. What am I missing?