Heroku Deployment

Have you checked the logs in the console or terminal by using heroku logs --tail?
I had the same problem when I deployed Strapi. I found that I couldn’t connect to the database because of unsecure connection (ssl).

I had to add this in database.js to make it to work.

ssl: {
  rejectUnauthorized: false
}

config/env/production/database.js

const parse = require('pg-connection-string').parse;
const config = parse(process.env.DATABASE_URL);

module.exports = ({ env }) => ({
  connection: {
    client: 'postgres',
    connection: {
      host: config.host,
      port: config.port,
      database: config.database,
      user: config.user,
      password: config.password,
      ssl: {
        rejectUnauthorized: false
      },
    },
    debug: false,
  },
});