curl --request POST \
  --url https://api.kit.com/v4/bulk/tags \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "tags": [
    {
      "name": "Test Tag 0"
    },
    {
      "name": "Test Tag 1"
    },
    {
      "name": "Test Tag 2"
    },
    {
      "name": "Test Tag 3"
    }
  ],
  "callback_url": null
}'

{
  "tags": [
    {
      "id": 3453,
      "name": "Existing Tag",
      "created_at": "2023-02-17T11:43:55Z"
    },
    {
      "id": 3454,
      "name": "Attended Event",
      "created_at": "2023-02-17T11:43:55Z"
    },
    {
      "id": 3455,
      "name": "Newsletter",
      "created_at": "2023-02-17T11:43:55Z"
    },
    {
      "id": 3456,
      "name": "Re-engage",
      "created_at": "2023-02-17T11:43:55Z"
    }
  ],
  "failures": []
}