Error 403 Forbidden: You don't have access to / on this server for simple Heroku build

Question

I've got a single page that I want to demo for a non-profit I'm volunteering for, but the Heroku deployment just gives me the error from the title. The file directory is such:

--hotlabdemo
    --assets    
        --javascript
            home.js
        --css
            style.css
        --images
            a few images
    composer.json
    home.html
    home.php

I have another page hosted there that is more or less the same thing, but a little different. The HTML/JS/CSS are different, but nothing that should prevent accessing the "/" on the server.

For reference, the php and composer for both pages are

{}

and

<?php include_once("home.html"); ?>

I opened a support ticket with Heroku, but was told

"Unfortunately, this appears to be an issue that falls outside the nature of
the Heroku Support policy. I recommend searching our Knowledge Base or 
asking the community on Stack Overflow for more answers."

Any thoughts on why I might be prevented from accessing the page?

Answer 1

You can most likely fix this issue by creating a file "Procfile" in the root of your project. https://devcenter.heroku.com/articles/procfile

NOTE

Procfile naming and location

A Procfile is a file named Procfile. It should be named Procfile exactly, and not anything else . For example, Procfile.txt is not valid. The file should be a simple text file.

The file must be placed in the root directory of your application. It will not function if placed in a subdirectory.

The Procfile should define that you want to run PHP Server eg

web: vendor/bin/heroku-php-apache2 web/

https://devcenter.heroku.com/articles/getting-started-with-php#define-a-procfile