"API limit exceeded" means your data source hit its request cap.
GA4 Quotas
Reduce charts querying GA4. Increase cache. Export to BigQuery (higher limits).
Sheets Limits
~300 requests/minute. Combine Sheets, use extracts, or migrate to BigQuery. See comparison.
Connector Limits
Community connector providers set their own limits per subscription tier.
Mitigation
Enable 12-hour caching. Reduce charts. Pre-aggregate in Sheets or BigQuery. Get an architecture assessment.