I am setting up i18next-http-middleware with my express app. My goal is to have the language detected based on the query string ‘lng’ for each request. When following the documentation as I understand it, I get this error:

TypeError: req.t is not a function

Here is my init setup:

const express = require("express");
const bodyParser = require("body-parser");
const i18next = require('i18next');
const middleware = require('i18next-http-middleware');
const Backend = require('i18next-fs-backend');

const logger = require('./util/logger');

const translationTest = require('./translationTest');

const router = express.Router();

router.use('/translation', translationTest);

i18next
    .use(Backend)
    .use(middleware.LanguageDetector)
    .init({
        ns: ['common'],
        defaultNS: 'common',
        preload: ['en', 'de'],
        fallbackLng: 'en',
        // supportedLngs: ['en', 'de'],
        detection: {
            order: ['querystring'],
            lookupQuerystring: 'lng',
            caches: false,
            ignoreCase: true
        },
        debug: true,
        backend: {
            loadPath: 'locales/{{ns}}/{{ns}}_{{lng}}.json'
        },
        initImmediate: false
        
    });

const app = express();
app.use(logger);
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
app.use('/', router);

app.use(middleware.handle(i18next));

const port = parseInt(process.env.PORT) || 3000;
const server = app.listen(port, () => {
    console.log(`Listening at http://localhost:${port}`);
});

And my test file:

const express = require('express');

const router = express.Router();

router.get("/", async (req, res) => {

    res.send(req.t('common:test'));
});

module.exports = router;