laravel project on cpanel subdomain error: HTTP ERROR 500

I have a confusing error with laravel 7 project. This project when I uploaded it into the main directory It worked successfully. but when I uploaded it into a subdomain it gives me 500 error. I did steps that mentioned in this answer but it didn’t work also How to set up a laravel project on cPanel subdomain? Hope someone help me

Answer

First Of All, I’d like to thank all contributors. I knew the reason for the error. In this image:
[![enter image description here][1]][1]

The file called public_html is not in the root directory as it might seem it is. It’s just a shortcut from : /domains/zigzagfamily.com/public_html So when I created a folder called chatbot in public_html, I wrote in index.php:

require __DIR__.'/../../chatbot/vendor/autoload.php';

$app = require_once __DIR__.'/../../chatbot/bootstrap/app.php';

And it’s wrong because as I said public_html is here:

/domains/zigzagfamily.com/public_html So when I go back two folders, I’m now in zigzagfamily.com So I must go back another two folders to be in the root directory to be able to access chatbot folder that is located in the root directory. Summery: the right code was:

require __DIR__.'/../../../../chatbot/vendor/autoload.php';

$app = require_once __DIR__.'/../../../../chatbot/bootstrap/app.php';