Bring nginx-container with fpm-config to work / Laravel

This work is based on the following tutorial:

https://www.howtoforge.com/dockerizing-laravel-with-nginx-mysql-and-docker-compose/

I have gone "succesfully" through all steps, but the nginx-container doesn't respond properly . Most of the times I get a HTTP 500/502 error message. The following reasons might be behind it, but I was unable to fathom it out:
- uid-assingment
- php-fpm config
- etc.

What differs from the tutorial is, that the nginx doesn't run on a subdomain. Everything runs on the domain.

If you feel comfortable with this task, feel free to apply.