How to use cron?

import express from 'express'
import { cron } from "https://deno.land/x/deno_cron/cron.ts";
const app  = express()

app.listen(3001, () => 
{ 
    console.log('\u{1F680} API running!') 
})

cron("*/60 * * * * *", () => {
  console.log('ok');
});