Issue to access the files of Deployed Shopify APP in Heroku

Issue summary

I'm facing an issue using the Heroku environment.
I have created the app in Heroku and deployed Shopify APP using Docker Container, which everything it went successfully.
But when the APP is installed in the Testing Shopify Store, I have the issue of not being able to find dev_embed.js. and could not have access to index.jsx.

Here are the issues that are appearing at the browser, and also heroku log file:

1. GET https://my-app.herokuapp.com/dev_embed.js net::ERR_ABORTED 404 (Not Found)
2. Access to script at 'https://my-shopify-store.myshopify.com/admin/oauth/..../index.jsx') from origin 'https://my-app.herokuapp.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Steps that I followed to fix the issue:

1. At web/nginx.conf, I have added:

 http {
     ...
         server {
         .... 
              # this part is added 
              location /dev_embed.js {
                    alias /app/web/frontend/dev_embed.js;
                }
         }
     }

2. At Procfile I have this code:

  web: vendor/bin/heroku-php-apache2 public/
  worker: php artisan migrate

Do I need to add additional configuration of the files that need to be load from any Shopify Admin Panel to Heroku Server?
Because right now I'm still having the issue even though I did the above changes.

Looking forward to any feedback/help.

Start with web/nginx.conf and the Procfile, then inspect how the deployed Heroku container serves dev_embed.js and index.jsx. Review the browser errors and Heroku logs to trace the 404 and CORS failures; done means the installed Shopify app can load both files from the deployed app without those errors.