Getting typeerror while trying to serve `index.html` using express.js

main.bundle.js?v=1708507092640:92 Uncaught TypeError: Cannot read properties of null (reading 'classList')
    at main.bundle.js?v=1708507092640:92:13000
    at NodeList.forEach (<anonymous>)
    at H (main.bundle.js?v=1708507092640:92:12781)
    at Ue (main.bundle.js?v=1708507092640:92:13511)
    at HTMLDocument.<anonymous> (main.bundle.js?v=1708507092640:92:5168)

app.get('/', async (req, res) => {
  res.sendFile(path.join(__dirname, '/docs/index.html'));
});