Invalid xml with RestSharp

当我使用 RestSharp 通过 API 在LinkedIn中分享我的帖子时，它向我显示错误

Invalid xml {Expected elements 'post-network-update@...........'

    public class LinkedInPost(string title, string description, string url, string imageUrl=null)
    {
       ApiBaseUrl111 = LLinkedInBaseUrllll;
        var request = new RestRequest("v1/people/~/shares?format=json", Method.POST);
        request.AddHeader("Authorization", "Bearer " + Token);
        request.AddHeader("Content-Type", "application/json; charset=utf-8");
        request.AddHeader("x-li-format", "json");
        //request.RequestFormat = DataFormat.Json;
        var model = new class
        {
            Comment = "This is my comment",
        LinkedInContent = new LinkedInContent
            {
                LinkedInDescription = description,
                LinkedInTitle = title,
                Submittedurl = url,
                Submittedimageurl = imageUrl
            },
            LinkedInVisibility = new LinkedInVisibility
                    {
                        LinkedInCode = "anyone"
                    }
        };
        request.AddJsonBody(model);
        var response = Execute<class>(request);
        return response;
    }