Facebook redirect with fbclid

$redirectFacebook = false;

// Fix stupid Facebook button restriction by checking the referer link
// and if comes from FB, go to specifified

if ($redirectFacebook) {
    $host = "https://domain.com/";
    $uri = "final-uri/";
    $location = "Location: " . $host . $uri;

    $refererUrl = strtolower($_SERVER['HTTP_REFERER']);
    $refererDomain = strpos($refererUrl, 'facebook');

    $whatINeed = explode('/', $_SERVER['REQUEST_URI']);
    $whatINeed = $whatINeed[1];

    if ($refererDomain !== false && $whatINeed != $uri) { // prevent circular thing

        if (isset($_GET["fbclid"])) {
            echo "Redirect to " . $_GET["fbclid"];
            $location = $location . "?fbclid=" . $_GET["fbclid"];
        }
        
        header($location, true, 302);
        exit;
    }
    
}