const options = {
  method: 'GET',
  headers: {'x-spree-api-key': '<api-key>', Authorization: 'Bearer <token>'}
};

fetch('http://{defaultHost}/api/v3/admin/translations', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

curl --request GET \
  --url http://{defaultHost}/api/v3/admin/translations \
  --header 'Authorization: Bearer <token>' \
  --header 'x-spree-api-key: <api-key>'

{
  "data": {
    "resource_type": "product",
    "default_locale": "en",
    "locales": [
      "de"
    ],
    "field_count": 5,
    "search_field": "name_cont",
    "coverage": [
      {
        "locale": "de",
        "translated": 0,
        "total": 1,
        "coverage": 0
      }
    ],
    "records": [
      {
        "id": "prod_UkLWZg9DAJ",
        "label": "Espresso Machine",
        "locales": {
          "de": 2
        }
      }
    ]
  },
  "meta": {
    "page": 1,
    "limit": 25,
    "count": 1,
    "pages": 1,
    "from": 1,
    "to": 1,
    "in": 1,
    "previous": null,
    "next": null
  }
}

{
  "error": {
    "code": "record_not_found",
    "message": "record not found"
  }
}