JsonStringToCsv.cs

// https://www.codeproject.com/Questions/1128427/JSON-to-CSV-converter
public static class JsonToCsv
{
public static void JsonStringToCSV(string jsonContent)
{
    XmlNode xml = JsonConvert.DeserializeXmlNode("{records:{record:" + jsonContent + "}}");
    XmlDocument xmldoc = new XmlDocument();
    xmldoc.LoadXml(xml.InnerXml);
    XmlReader xmlReader = new XmlNodeReader(xml);
    DataSet dataSet = new DataSet();
    dataSet.ReadXml(xmlReader);
    var dataTable = dataSet.Tables[0];

    //Datatable to CSV
    var lines = new List<string>();
    string[] columnNames = dataTable.Columns.Cast<DataColumn>().
                                      Select(column => column.ColumnName).
                                      ToArray();
    var header = string.Join(",", columnNames);
    lines.Add(header);
    var valueLines = dataTable.AsEnumerable()
                       .Select(row => string.Join(",", row.ItemArray));
    lines.AddRange(valueLines);
    File.WriteAllLines($"./data_{Guid.NewGuid()}.csv", lines);
}