curl --request GET \
  --url https://api.wellapp.ai/v1/invoices/{id}

{
  "data": {
    "type": "invoice",
    "id": "<string>",
    "attributes": {
      "reference_number": "<string>",
      "document_type": "commercial_invoice",
      "document_type_code": "380",
      "issue_date": "2023-12-25",
      "due_date": "2023-12-25",
      "currency": "<string>",
      "totals": {
        "items_total": 123,
        "tax_total": 123,
        "grand_total": 123
      },
      "terms": "<string>",
      "status": "draft",
      "payment_status": {
        "paid": true,
        "amount_paid": 123,
        "amount_remaining": 123
      },
      "billing_context": "<string>",
      "description": "<string>",
      "created_at": "2023-11-07T05:31:56Z",
      "updated_at": "2023-11-07T05:31:56Z"
    },
    "relationships": {
      "issuer": {
        "data": {
          "type": "<string>",
          "id": "<string>"
        }
      },
      "receiver": {
        "data": {
          "type": "<string>",
          "id": "<string>"
        }
      },
      "documents": {
        "data": [
          {
            "type": "<string>",
            "id": "<string>"
          }
        ]
      },
      "related_documents": {
        "data": [
          {
            "type": "<string>",
            "id": "<string>"
          }
        ]
      }
    },
    "links": {
      "self": "<string>"
    }
  },
  "included": [
    {
      "id": "<string>",
      "type": "document",
      "attributes": {
        "file_name": "<string>",
        "partner_id": "<string>",
        "customer_id": "<string>",
        "user_identifier": {
          "uuid": "<string>",
          "email": "<string>",
          "phone_number": "<string>"
        },
        "status": "<string>",
        "uploaded_at": "2023-11-07T05:31:56Z",
        "processed_at": "2023-11-07T05:31:56Z",
        "file_type": "<string>",
        "size_bytes": 123
      },
      "links": {
        "download": "<string>"
      }
    }
  ]
}