Problem with express route

This is my server:

const express = require('express');
const morgan = require('morgan');
const app = express();

const { mongoose } = require('./database');

// Settings
app.set('port', process.env.PORT || 3000);
var port = app.get('port');

// Middlewares
app.use(morgan('dev'));
app.use(express.json());

// Routes
app.use('api/employees', require("./routes/employee.routes"));


//Starting the Server
app.listen(port, ()=> {
  console.log("Server on port: ", port);
});

it works fine and connects to the database very well. What does not work is the route:

app.use('api/employees', require("./routes/employee.routes"));

that every time I follow it localhost: 3000 / api / employees it returns the status code 404

This is the route:

const express = require('express');
const router = express.Router();

const employee = require('../controllers/employee.controller');

router.get('/', employee.getEmployees);

module.exports = router;

and of course here I have the driver:

const employeeCtrl = {};

employeeCtrl.getEmployees = (req,res) => {
  res.json({
    status: 'Employees Here'
  })
}

module.exports = employeeCtrl;

Why do I get that error?