How to display a page that is not on FTP?

Question

JavaScript

Hello. Actually, the topic is in the question. For better understanding, I will give an example:
When an article is created in any CMS, for example, at /about, then no corresponding page is created at this address. But at the same time, a fully capable page is displayed at this address based on a specific template and information taken from somewhere.

What exactly I need (including more or less general information on the question asked): how to implement a redirect / replacement of the "page" at /register to the page /index.php?action=register, so that the URL does not change, but the entire template is taken from the corresponding index?

Answer 1

Relatively speaking, all information about the page is taken from the database.
There is a php script that extracts information from the database and inserts it into the right places in the template.
In order for another page to open at /index.php?action=register, you need to organize the processing of GET parameters in the index.php script, and when the action variable is set to "register", the page is replaced by /register.
If you own php, then there should be no problems with writing code.
Full code that cut the toaster:

if ($_SERVER['QUERY_STRING']) {
header('HTTP/1.0 404 Not Found');
echo ('
<script type="text/javascript">
  location.replace("/404.html");
</script> 
');
exit();
}