Small bug resolution

The path of the called file is correct, and I am using an absolute path, so the path is fine.

So what is the problem? It is very simple. Order.php in the file has the first letter of Order in capital letters. php, when I call it, it is order.php

If I change it to uppercase, it will be no problem!

Actually, I know that the file is in uppercase letters, but I think the call should be case-insensitive, so I just write it in lowercase

Every time you learn, you will gain wisdom!

The above has introduced the solution to small bugs, including aspects of it. I hope it will be helpful to friends who are interested in PHP tutorials.