API server with Postgres on Deno Deploy ConnectionParamsError

import { Pool } from "https://deno.land/x/postgres@v0.19.3/mod.ts";

Deno.serve(async (req) => {
  return new Response("Not Found", { status: 404 });
});

// Get the connection string from the environment variable "DATABASE_URL"
const databaseUrl = Deno.env.get("DATABASE_URL")!;

// Create a database pool with three connections that are lazily established
const pool = new Pool(databaseUrl, 3, true);

Deno.serve(async (_req) => {
  try {
    // Grab a connection from the pool
    const connection = await pool.connect()
 
    try {
      // Run a query
      const result = await connection.queryObject`SELECT * FROM animals`
      const animals = result.rows 
    } finally {
      // Release the connection back into the pool
      connection.release()
    }
  } catch (err) {
    console.error(err)
    return new Response(String(err?.message ?? err), { status: 500 })
  }
})