Analytics Export API 429 during JMeter Load Test on US1

Looking for advice on handling rate limits for analytics exports. Running JMeter 5.6 against /api/v2/analytics/reportingdata/export on Genesys Cloud US1. Pushing 50 concurrent threads triggers HTTP 429 immediately.

“Export requests are subject to standard API rate limits.”

Is there a specific header or retry logic required for bulk data pulls? The standard backoff strategy in JMeter is not helping with the initial burst. Need to validate throughput for daily reporting jobs.