Error in list items

[juanxodj]

When I want to list items like this:

$plans = $provider->listPlans();
$products = $provider->listProducts();

I am getting this error:

Apparently in the url parameters 'true' is being sent as a string and not as a boolean in total_required.

Even passing parameters to the function as the documentation says it returns the same error:

$fields = ['id', 'product_id', 'name', 'description'];
$plans = $provider->listPlans(1, 30, true, $fields);

My code: