curl --request POST \
  --url https://api.thehaystack.ai/v2/haystack/speakers/{speakerId}/image/upload \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form image='@example-file'

{
  "speakerId": 123,
  "filename": "<string>",
  "url": "<string>"
}