curl --request POST \
  --url https://api.sandbox.isometric.com/mrv/v0/sources \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'x-client-secret: <x-client-secret>' \
  --data '{
  "__typename": "<string>",
  "content_length": 123,
  "content_type": "<string>",
  "display_name": "<string>",
  "file_name": "<string>",
  "is_public": false,
  "published_at": "2023-12-25",
  "supplier_reference_id": "<string>"
}'

{
  "signed_upload_url": "<string>",
  "source": {
    "display_name": "<string>",
    "id": "src_1EBBF4M7X1S06G1Y",
    "is_public": true,
    "published_at": "2023-12-25",
    "supplier_reference_id": "<string>",
    "type": "DOCUMENT",
    "url_info": {
      "__typename": "SourcePublicUrlInfo",
      "url": "<string>"
    }
  }
}