What the procfile file needs to have to run a Deno fresh app in Heroku?

Question

I'm using heroku to run my fresh app so I'm adding a Procfile. I find some examples running like this but it's not working. The port is not bound property so my guess it's that I need to make some changes in my fresh app too.

What should I change in my fresh app to bind Heroku port

Procfile:

web: deno run --allow-read --allow-end --cached-only main.ts --port=${PORT}

Runtime.txt

v1.26.1

Buildpack URL: https://github.com/chibat/heroku-buildpack-deno.git

main.ts

import { start } from "$fresh/server.ts";
import manifest from "./fresh.gen.ts";

import twindPlugin from "$fresh/plugins/twind.ts";
import twindConfig from "./twind.config.ts";

await start(manifest, { plugins: [twindPlugin(twindConfig)] });