i18next Module in ExpressJS and Client Side

I'm using i18next module in my NodeJs/ExpressJS web application.

The translation files are in /locales folder.

From i18next.com, it can be used in client side

<script type="text/javascript" src="[PATH]/i18next.js" />
...
<span href="#" data-i18n="nav.home"></span>

I installed the module via npm install i18next.

In app.js, I set static files:

app.use(express.static(path.join(__dirname, 'public')));

How to refer to the path of i18next.js file in client side? The path for the translation files?

<script type="text/javascript" src="???" />

Thanks