const labels = [
  { externalId: 'PUMP', name: "Pump" },
  { externalId: 'ROTATING_EQUIPMENT', name: 'Rotating equipment', description: 'Asset with rotating parts' }
];
const createdLabels = await client.labels.create(labels);

{
  "items": [
    {
      "externalId": "my.known.id",
      "name": "<string>",
      "createdTime": 1730204346000,
      "description": "<string>",
      "dataSetId": 4503599627370496
    }
  ]
}