curl --request POST \
  --url https://api.cartesia.ai/voice-changer/sse \
  --header 'Cartesia-Version: <cartesia-version>' \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-Key: <api-key>' \
  --form clip='@example-file' \
  --form 'voice[id]=<string>' \
  --form 'output_format[sample_rate]=123' \
  --form 'output_format[bit_rate]=123'

{
  "done": false,
  "status_code": 206,
  "step_time": 123,
  "data": "aSDinaTvuI8gbWludGxpZnk=",
  "sample_rate": 44100
}