How to pick up a hidden GET request in httacess?

Question

htaccess

Good afternoon!
How to hide GET request in httacess.
There are pages like
site.com/gallery/dog
site.com/gallery/cat It is
necessary that when navigating through them, a query like this is taken:
site.com/gallery/?cat=dog
site.com/gallery/?cat=dog
So that the user does not saw ?cat= and php handled it.

Answer 1

RewriteEngine On
RewriteRule ^gallery/(.*)$ /gallery/?cat=$1 [L]

Answer 2

if (!empty($_GET['test'])) {
    // что-то делать с параметром test из GET-запроса
    var_dump($_GET['test']);
}

It's in the 2_page.php code. Don't forget to validate your input.