And still doesn't work. I don't know how to insert username in db on the another way?
What do you mean it does not work? did you actually make a text file with the name "get-user-list.php" and saved it in (C:\xampp\htdocs), also is your Apache Server running? I think there is a mistake in the document, file sserver is in this path > btcpool-master\docker\btcpool\test\btc\cfg. So you need to open sserver.cfg with a notepad and go to line 107
list_id_api_url = "http://userlist/userlist.php";
change the path to
list_id_api_url = "http://get-user-list.php";
This assumes you saved the get-user-list.php file directly in htdocs without a sub-folder, I think the explanation by SwimmingTiger on GitHub is straightforward, he skipped a few things based on the assumption that anyone who gets this far should at least have a basic idea about what they are doing.
Let me know how it goes.