You need to import the default export from express instead of the namespace (which is an object with all named exports).
In your app.ts this should be all you need:
// Change these
import express from "express";
import bodyParser from "body-parser";
The difference is:
// Namespace import
import * as express from "express";
const app = express.default();
// Default import
import express from "express";
const app = express();