Why is there an error in vk api appWidget.Update?

Question

PHP

Call the appWidget.Update method with the following parameters

$data = array(
    
    'type' => 'list',
    'access_token' => $token,
    'v' => '5.73',
    'code' => '
    var u = API.users.get()[0];
    var name = u.first_name + " " + u.last_name;
    var id = u.id; 
        return {
            "title": "Тест",
            "rows":
                [
                    { "title": "Лучший пользователь - " + name,"descr": "Да-да, это ты.","icon_id" : "id" + id}
                ]
            
        };'
);

An error occurs
[error_code] => 100
[error_msg] => One of the parameters specified was missing or invalid: rows[0].icon_id is not valid user id
[request_params] => Array
However, the call from the application itself via js with the same parameters

let execute = 'var u = API.users.get()[0];var name = u.first_name + " " + u.last_name; var id = "id" + u.id; return {"title": "тест", "rows": [{ "title": "Лучший пользователь - " + name, "icon_id" : id, "descr": "Да-да, это ты."}]};'; 

VK.callMethod("showAppWidgetPreviewBox", 'list', execute)

works great.
Why? How can this be fixed? Or is there some other way to display the user's avatar?
I also tried to get Photo_id and run with it, the same error