Trace REST API Throttling

[euclidean]

I am using the Splunk Observability REST API, specifically "/apm/trace" endpoint.  

I have following questions about throttling limits, which triggers HTTP code 429: 

- What is the limit?
- If this is configured anywhere within Splunk Observability?
- What types of throttling?  such as Hard, Soft, or Elastic / Dynamic
- Does it use fixed window or rolling window, with or without counters?

Thanks!