Produce a looping background ambiance soundscape from a text description, such as "windy forest at dusk" or "busy tavern interior". The job result is a single audio result containing a URL. The description field is required and duration is capped at 10 seconds (0 means auto-pick based on the description). Credits are held when the job is accepted and refunded if it fails or is cancelled. Use this for continuous, atmospheric background loops; use createSoundEffect for short discrete sound effects, createMusic for musical pieces, and createAudioTransform to remix an existing audio sample. Pass an optional request_id to tag the result so you can locate it later via listGenerations (type audio). Requires an API key (user scope). The call returns 202 with a job id - poll getApiJob (pass wait 30 to long-poll) honouring poll_after_ms, until status is succeeded; its result field is exactly the response documented for this operation. Synchronous responses are deprecated but still supported: pass `async: false` to block until the result is ready and receive it as the response body. Synchronous calls run on the same queue: the response carries an X-Ludo-Job-Id header, and a job still running after 15 minutes comes back as 202 with the job instead of an error. Each account may have up to 50 generations queued or running at once via the API; a request beyond that returns 429 (code PENDING_JOBS_LIMIT).