strapi-plugin-i18n/admin/src/utils/getLocaleFromQuery.js

This plugin enables to create, to read and to update content in different languages, both from the Admin Panel and from the API

import get from 'lodash/get';

const getLocaleFromQuery = query => {
  return get(query, 'plugins.i18n.locale', undefined);
};

export default getLocaleFromQuery;