Nodejs express Why can’t my route point to the secondary directory?

  node.js, question

I made the template output in html format through ejs

module.exports = function (app) {
 app.get('/dropload', function (req, res) {

If I put index in the dropload folder and change the top address to’. /dropload’ access, there will be no problem.
But when I put this file under. /dropload/client, the address above will be changed to this address, and an error will be reported.
req.render is not a function
Why is this? I can’t do it for a long time (▼-▼)

req.renderYou used it here. YesreqAh.renderThe method is as followsresUp there.