Zendesk App Hosting

I am working on a server-side app using the React scaffold. I used the Event Timeline app example from here as a starting point. So my app.js code is very similar to that example.

While testing, I have also successfully displayed sample data from my Databricks SQL warehouse into my Zendesk app. The following is some code I am using in my backend.js file to get that data from Databricks: 

const express = require('express');
const { DBSQLClient } = require('@databricks/sql');
const cors = require('cors');

const app = express();
const port = process.env.PORT || 3000;

const corsOptions = {
  origin: 'http://localhost:4567'
}
app.use(cors(corsOptions));

var token          = process.env.DATABRICKS_TOKEN;
var serverHostname = process.env.DATABRICKS_SERVER_HOSTNAME;
var httpPath       = process.env.DATABRICKS_HTTP_PATH;

if (!token || !serverHostname || !httpPath) {
  throw new Error("Cannot find Server Hostname, HTTP Path, or personal access token. " +
                  "Check the environment variables DATABRICKS_TOKEN, " +
                  "DATABRICKS_SERVER_HOSTNAME, and DATABRICKS_HTTP_PATH.");
}

const client = new DBSQLClient();

app.get('/api/query', async (req, res) => {
  try {
    await client.connect({
      token: token,
      host: serverHostname,
      path: httpPath
    });

    const session = await client.openSession();

    const queryOperation = await session.executeStatement(
      statement = `SELECT fare_amount FROM samples.nyctaxi.trips LIMIT 3`,
      options   = {
        runAsync: true,
        maxRows: 10000 // This option enables the direct results feature.
      }
    );

    ... // other code here
});

app.listen(port, () => {
  console.log(`Server started on port ${port}`);
});

In my frontend (app.js), I make a GET request to the endpoint here in my backend.js (http://localhost:3000/api/query) and the results of the SQL query are fetched and displayed in my Zendesk App.

If my understanding is correct, I can host the backend part of my app in AWS, Heroku or a similar service. 

My question is, could I host the backend in Zendesk instead? If so, how would I implement and configure this?

Also, if I should edit some part of my code to implement this, please provide an example or suggestion.