How to create dynamic model with a schema in mongoose

app.js

const http = require('http');
const express = require('express');
const mongoose = require('mongoose');

const app = express();
const server = http.Server(app);

const connectionUri = 'mongodb://localhost/dbtest';

mongoose
  .connect(connectionUri, { useNewUrlParser: true })
  .then(() => {
    console.log('Connection to database established');
  })
  .catch(err => {
    console.log(err);
    process.exit(-1);
  });

const Schema = mongoose.Schema;

const UserInfoSchema = new Schema({
  note: String,
  timeline: { type: Date, default: Date.now }
});

app.get('/add/:id/:note', async (req, res) => {
  const { id, note } = req.params;
  // Retrieve model which contain info documents of user with id
  const UserInfo = mongoose.model('User_' + id, UserInfoSchema);

  const log = new UserInfo({ note });
  await log.save();
  res.send(log);
})

app.get('/:id', async (req, res) => {
  const { id } = req.params;
  // Retrieve model which contain info documents of user with id
  const UserInfo = mongoose.model('User_' + id, UserInfoSchema);

  const logs = await UserInfo.find();
  res.send(logs);
})


server.listen('8080', () => console.log('Listening on 8080'));

package.json

{
  "name": "test",
  "version": "0.0.0",
  "private": true,
  "scripts": {
    "start": "node app.js"
  },
  "dependencies": {
    "express": "~4.16.0",
    "mongoose": "^5.4.0"
  }
}

I am trying to do something similar, but when my server restarts and I try to fetch again the data, it says the schema is not registered.