import Telnyx from 'telnyx';

const client = new Telnyx({
  apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted
});

const supportingDocument = await client.portouts.supportingDocuments.create(
  '182bd5e5-6e1a-4fe4-a799-aa6d9a6ab26e',
);

console.log(supportingDocument.data);

{
  "data": [
    {
      "id": "5a16902a-2ee9-4882-a247-420fc6627b62",
      "record_type": "supporting_document",
      "type": "loa",
      "portout_id": "0ccc7b54-4df3-4bca-a65a-3da1ecc777f0",
      "document_id": "f1c5e079-9d82-4f50-95bc-ae2f6b8d84d7",
      "created_at": "2018-02-02T22:25:27.521Z",
      "updated_at": "2018-02-02T22:25:27.521Z"
    }
  ]
}