curl --request POST \
  --url https://api.sandbox.getasset.com/v0/business/{business_id}/document \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form 'files=<string>' \
  --form 'task_id=<string>' \
  --form files.items='@example-file'

{
  "data": {
    "business_id": "<string>",
    "name": "<string>",
    "description": "<string>",
    "document_type": "receipt",
    "file_size": 123,
    "status": "processing",
    "external_account_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "id": "<string>",
    "created_at": "2023-11-07T05:31:56Z",
    "task_id": "tsk_R2fAXCjqJPdpYata112zyW",
    "transaction_id": "txn_R2fAXCjqJPdpYata112zyW",
    "metadata_": {}
  }
}