I want to use Dazah app: https://github.com/Dani28/Dazah-Business-Networking as a means of members log in. What does this mean "Upload all files to the document root of a PHP-capable web server (nginx, apache, etc.)"?

I feel that all files should be inside some folder, e.g., root/dazah or something like that? If so, what should be the name of the Dazah app folder?

I replied to you via PM, but for anyone else who should come across this thread, I'll repeat myself.

There is nothing else you should need for Dazah app to work apart from the installation instructions on Github. The instructions specify importing our audience, but you can alternatively create your own audience or even import DaniWeb's audience into your app.

You can name the folder whatever you want. If you name it root/dazah then it will be accessible at https://www.yourdomain.com/dazah/

Step 2 of the installation instructions asks you to specify the URL of where the app is located, so this will include the folder name you are using.