The translation requests are routed to the best Machine Translation engine for the language pair according to the latest Intento evaluation report (https://bit.ly/mt_jun2019). Depending on the language pair, it may be Amazon, Baidu, DeepL, Google, Microsoft, ModernMT, Tencent, or Yandex.
Intento Plugin requires a commercial API key for Intento API (https://inten.to).