Highcharts has an export server and they had some examples in their GitHub repo:
https://github.com/highcharts/node-export-server/blob/master/tests/node/scenarios/custom_code_from_string.json

If you copy any of the examples and call the export server https://export.highcharts.com
it gets back as a bad request.

This is not working:

{export:
 {
  // JSONDATA
 }
}

This is working:

{
  // JSONDATA
}

The problem is the export server only accept the export object body. So if I want to use the callback I can’t cause it is in a different block.

Here is my simple console app getting image from the export server:

using System.Net.Http.Headers;
using System.Text;

namespace chartImageScraper
{
    class Program
    {
        static async Task Main(string[] args)
        {
            string apiUrl = "https://export.highcharts.com/";

            // 400 Bad Request cause the JSON structure and the custom logic in it.
            //string jsonData = "{rn  "export": {rn    "options": {rn      "chart": {rn        "type": "column"rn      },rn      "title": {rn        "text": "Custom code (from string)"rn      },rn      "yAxis": [rn        {rn          "title": {rn            "text": "Primary axis"rn          }rn        },rn        {rn          "opposite": true,rn          "title": {rn            "text": "Secondary axis"rn          }rn        }rn      ],rn      "plotOptions": {rn        "column": {rn          "borderRadius": 5rn        }rn      },rn      "series": [rn        {rn          "data": [1, 3, 2, 4]rn        },rn        {rn          "data": [324, 124, 547, 221],rn          "yAxis": 1rn        }rn      ]rn    }rn  },rn  "customLogic": {rn    "allowCodeExecution": true,rn    "allowFileResources": true,rn    "customCode": "Highcharts.setOptions({chart:{events:{render:function (){this.renderer.image('https://www.highcharts.com/samples/graphics/sun.png',75,50,20,20).add();}}}});"rn  }rn}";

            // Gets image and 200 result but the custom logic is obviously missing.
            string jsonData = "{rn    "options": {rn      "chart": {rn        "type": "column"rn      },rn      "title": {rn        "text": "Custom code (from string)"rn      },rn      "yAxis": [rn        {rn          "title": {rn            "text": "Primary axis"rn          }rn        },rn        {rn          "opposite": true,rn          "title": {rn            "text": "Secondary axis"rn          }rn        }rn      ],rn      "plotOptions": {rn        "column": {rn          "borderRadius": 5rn        }rn      },rn      "series": [rn        {rn          "data": [1, 3, 2, 4]rn        },rn        {rn          "data": [324, 124, 547, 221],rn          "yAxis": 1rn        }rn      ]rn    }rn  }";

            using (HttpClient client = new HttpClient())
            {
                client.BaseAddress = new Uri(apiUrl);
                // Adding necessary headers
                client.DefaultRequestHeaders
                    .Accept
                    .Add(new MediaTypeWithQualityHeaderValue("application/json"));

                // Sending POST request with JSON data
                HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, "relativeAddress");
                request.Content = new StringContent(jsonData, Encoding.UTF8, "application/json");

                HttpResponseMessage response = await client.SendAsync(request);

                var test = response.Content.ReadAsStringAsync().Result;

                // Checking if request was successful
                if (response.IsSuccessStatusCode)
                {
                    // Reading response content as a byte array
                    var imageData = await response.Content.ReadAsByteArrayAsync();

                    // Saving the image file
                    await File.WriteAllBytesAsync($"chart_image_{DateTime.Now:yyyyMMddHHmmss}.png", imageData);

                    Console.WriteLine("Image saved successfully.");
                }
                else
                {
                    Console.WriteLine($"Failed to retrieve image. Status code: {response.StatusCode}");
                }
            }
        }
    }
}

I put the jsonData variable the good and the bad examples (need to uncomment it). It is clear that Hihghcharts own examples not working at all on their server.
Am I doing something wrong or why it is not working?
Thank you!

I tried a lot of things and I would like to know why the Highcharts example not works on the Highcharts export server? If it is possible I would like to get a working example with the custom JS functions. Like update title or values in the chart with JS code.