I am using the Forge API.
I need to execute PATCH request.
When I send it using Postman everything is fine, but when I build request using HttpRequestMessage I get a response - "415 unsupported media type".
By API documentation Content-Type I set to "application/vnd.api+json".

Body of request in Postman

[![enter image description here](https://i.stack.imgur.com/p4aCw.png)](https://i.stack.imgur.com/p4aCw.png)
[Headers of request in Postman](https://i.stack.imgur.com/6E7QJ.png)

[request object structure](https://i.stack.imgur.com/5ezjd.png)

```
JObject jsonApi = new JObject();
            jsonApi.Add("version", "1.0");
            JObject attributes = new JObject();
            attributes.Add("displayName", file.FileName);
            JObject data = new JObject();
            data.Add("type", "items");
            data.Add("id", file.ExternalFileId);
            data.Add("attributes", attributes);

            JObject request = new JObject();
            request.Add("jsonapi", jsonApi);
            request.Add("data", data);

            using (var httpClient = new HttpClient())
            {
                HttpRequestMessage http = new HttpRequestMessage
                {
                    RequestUri = new Uri(url),
                    Method = new HttpMethod("PATCH"),
                    Headers =
                    {
                        { HttpRequestHeader.Authorization.ToString(), "Bearer " + userLastAccessToken },
                        { HttpRequestHeader.Accept.ToString(), "application/vnd.api+json" }
                    }
                };  
                http.Content = new StringContent(request.ToString(), Encoding.UTF8, "application/vnd.api+json");
                HttpResponseMessage responseMessage = await httpClient.SendAsync(http);
            }

```