The stock_status parameter does not work in API Woocommerce from flutter

I'm working with flutter and woocommerce_api: ^0.1.0 . I'm trying to get all the products in a category that have stock_status=instock but that parameter doesn't work. The same api consumed from PHP does work, so something in flutter is wrong. I've tried all the ways but I can't get it to work.

If I add the parameter ?category=113 , it does work so some parameters are accepted, but if I add the stock_status not working. I have hidden the keys for security reasons Any help?

 Future getProduct(int idCategory) async {
        WooCommerceAPI wooCommerceAPI = WooCommerceAPI(
            url: "x",
            consumerKey: "x",
            consumerSecret: "x");
    
        var productos = await wooCommerceAPI
            .getAsync("products?stock_status='instock'&per_page=100");
        return productos;
      }