Shopify PHP API - FileSessionStorage issue

[rockstar08]

require_once 'vendor/autoload.php';
include 'config.php';

use Shopify\Auth\OAuthCookie;

use Shopify\Context;

use Shopify\Client;

use Shopify\Auth;

use Shopify\Auth\FileSessionStorage;

Context::initialize(

    apiKey: $apiKey,

    apiSecretKey: $apiSecret,

    scopes: $scope,

    hostName: $shopName ,

    sessionStorage:  new FileSessionStorage(__DIR__.'/tmp/php_sessions'),

    apiVersion: '2023-04',

    isEmbeddedApp: true,

    isPrivateApp: false,

);

getting this error:

Parse error: syntax error, unexpected identifier "string", expecting variable in ....shopify-apps\src\Auth\FileSessionStorage.php on line 12

this s the function in FileSessionStorage.php :

   public function __construct(string $path = '/tmp/shopify_api_sessions')

    {

        if (!is_dir($path)) {

            mkdir($path);

        }

        $this->path = $path;

    }

Can anyone help with fixing this.. tried this too
SessionStorage:  new FileSessionStorage('/tmp/php_sessions'),