Can I use Google Analytics on URL shortener redirects powered by PHP?

Question

I have a short URL website like Bitly which currently redirect users with PHP from my site to a site of their choice. I want to add Google Analytics to the redirect pages but I am stuck on the problem where Javascript is run after the PHP code is executed so it wont work.

Bellow is the last part of the PHP code that redirects users from the short URL to the URL they shortend. I wonder if there is anyway to make this work OR change my code somehow so that Google Analytics can be executed either with PHP or something else that can do the "redirection"?

$shortUrlObj contains the short url code. If the short url is https://example.com/1234 $shortUrlObj contains 1234. fullUrl is the website destination they choose to shorten. So if the user shortened https://stackexchange.com, fullUrl contains https://stackexchange.com

switch ($redirect)
{
    default:
        header('HTTP/1.1 302 Moved Temporarily');
        redirect($shortUrlObj->fullUrl);
        break;
}

Answer 1

I got it working by using Javascript to do the redirecting. However the redirect became extremely slow when loading. Does anyone know why and what can be done about that part?

switch ($redirect)
{
     default:  
?>

    <script async src="https://www.googletagmanager.com/gtag/js?id=UA-xxxx-1"></script>
    <script>
    window.dataLayer = window.dataLayer || [];
    function gtag(){dataLayer.push(arguments);}
    gtag('js', new Date());
    
    gtag('config', 'UA-xxxxxx-1');
    </script>

    <script>
    window.location = '<? echo $shortUrlObj->fullUrl; ?>'
    </script> 
    
<?php
    break;
}