JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://i18next.com/public/download/latest/i18next.js"></script>
<span data-i18n=key>...</span>

JavaScript

var resources = {
    ru: {
        translation: {'key': 'russian'}
    },    
    en: {
            translation: {'key': 'english'}
        }
    };
i18n.init({
    lng: "ru",
    resStore: resources
});
Array.prototype.forEach.call (document.querySelectorAll ('[data-i18n]'), function (element){
   element.textContent = i18n.t (element.getAttribute ('data-i18n')); 
});