Using_Weglot_CDN.js

function encode(str) {
  return encodeURIComponent(str).replace(
    /[!'()*]/g,
    x =>
      `%${x
        .charCodeAt(0)
        .toString(16)
        .toUpperCase()}`
  );
}

function formatter(key, value) {
  return value === null
    ? encode(key)
    : [encode(key), "=", encode(value)].join("");
}

function stringify(obj) {
  if (!obj) {
    return "";
  }
  return Object.keys(obj)
    .map(key => {
      const value = obj[key];
      if (value === undefined) {
        return "";
      }
      if (Array.isArray(value)) {
        const result = [];
        for (const element of value.slice()) {
          if (element !== undefined) {
            result.push(formatter(key, element));
          }
        }
        return result.join("&");
      }
      return formatter(key, value);
    })
    .filter(x => x.length > 0)
    .join("&");
}

var params = {
  l_from: 'en',
  l_to: 'fr',
  words: JSON.stringify([{ t: 1, w: 'Hello' }]),
  request_url: window.location.href,
  api_key: "wg_xxxx"
};

// GET request with whole object in URL
fetch(`https://cdn-api.weglot.com/translate?${stringify(params)}`).then(console.log)

/*
{
  "l_from": "en",
  "l_to": "fr",
  "bot": 0,
  "title": "",
  "request_url": "https://cdn-api.weglot.com/translate",
  "from_words": [
    "Hello"
  ],
  "to_words": [
    "Bonjour"
  ]
}
*/