curl --location --request PUT 'https://app.sbai.cloud/api/external/upload' \
--header 'client-id: your-client-id' \
--header 'private-key: your-private-key' \
--header 'secret: your-secret' \
--form 'files=@/path/to/file1.pdf' \
--form 'files=@/path/to/file2.pdf'

{
  "message": "The files has been uploaded and is being processed. Please wait a moment."
}