hide the URL path of the download file using .htaccess file

I took whole day making tries to get this URL hidden from the address bar or inside the PDF Document.

Here in the stack overflow there are a ton of samples, but I didn't get any of them up and running.

1. I am generating a PDF file with a [ link ] inside.
2. This link has a dynamic parameter
3. This link will generate another file to be downloaded.
4. I would like hide the URL path displayed inside the PDF file.
5. When we hover the mouse pointer over the [ link ], it displays the file's directory..

Instead of display this in the file:
https://msia.com/wp-content/themes/astra-child/pdf.php?key=1547

I need to display only this

https://msia.com/

code

$order_url = "https://msia.com/wp-content/themes/astra-child/pdf.php?key=";

$url = '<a href="'.$order_url.$order_id.'"><b>Download PDF</b></a>'; 

$order_id = receives the dynamic id. Eg: 1547

This is what I have tried:

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST}  ([^/]+)\.example\.com.*
RewriteCond %{REQUEST_URI}  ^/([^/]+)$
RewriteRule .*  http://%1.msia.com/somepath/%1/%2 [L]

RewriteRule ^https://msia.com  https://msia.com/wp-content/themes/astra-child/pdf.php [NC,L]

# sends all requests from “/” to “/Site/am/index.php”
RewriteRule ^https://msia.com/wp-content/themes/astra-child/pdf.php$ https://msia.com

With this example, I lost complete the CSS formation of the link - PDF file is not a browser to render JS.

<a href="http://www.google.com" id="no-link">Hyperlink</a>

$(document).ready(function () {
          setTimeout(function () {
               
                $('a[href]#no-link').each(function () {
                    var href = this.href;
    
                    $(this).removeAttr('href').css('cursor', 'pointer').click(function () {
                        if (href.toLowerCase().indexOf("#") >= 0) {
    
                        } else {
                            window.open(href, '_blank');
                        }
                    });
                });
    
          }, 500);
    });

source https://stackoverflow.com/questions/70128471/hide-the-url-path-of-the-download-file-using-htaccess-file