How to access model data using mongoose?

Question

Since I have used first time node.js in es6 style. I am not able to fetch the data.

UserModel.js :

import mongoose from 'mongoose';
var userSchema = new mongoose.Schema({
      username: { type: String, unique: true },
      password: String
});
var User = mongoose.model('Users', userSchema);
export default User;

In Controller (custom style):

import User from '../schema/UserModel';
const UserCtrl = {};
UserCtrl.getUser =  (req, res) => {
      log(' In User Controller=========='); // ok
      try {
        const user = User.find({username: 'me'},(err, userDoc)=>{
          res.send(userDoc); 
        });
      }
      catch(err) {
        error('Error in getting user- ' + err); 
       // Error in getting user- TypeError: User.find is not a function
        res.status(400).send('not ok');
      } 
}
export default UserCtrl;

routes : app.get('/getUser', UserCtrl.getUser); // ok 

mongoose: v5 express: v4

Please help me.