Issue with GraphQL on Flutter

[sherwin_de jesu]

Hi,

Im trying to use GraphQL using Flutter. But I keep on getting "Unable to unserialize value." error. I've been googling for this for hours and still get not getting the expected result.

My code below:

Future<void> fetchPost() async {
      final String url =
          'http://m23ee-mag2-demo.datasolution-aspac.site/graphql';
      final String requestBody = """
                                {
                                  products(search: "shirt") {
                                    items {
                                      sku
                                      name
                                      description {
                                        html
                                      }
                                      small_image {
                                        url
                                      }
                                    }
                                  }
                                }
                                """;
      Map<String, String> requestHeaders = {
        'Content-type': 'application/json'
      };
      final response =
          await http.post(url, headers: requestHeaders, body: requestBody);

      if (response.statusCode == 200) {
        print(json.decode(response.body));
      } else {
        // If that response was not OK, throw an error.
        //throw Exception('Failed to load post');
        print(response.body);
      }
    }