How can i format a json body in c#?

How can i format the following into a json body in c# ?

    {
    id = "123"
    SessionId =""
    Sorting = [{ field = "EventDateTime", dir = "desc" }]
    Group = []
   }

I would usually declare

     var body = new
    {

       id = "123" ,
       SessionId =""
      ???
   }
request.AddJsonBody(body);

But these 2 are not formatting correctly

Sorting = [{ field = "EventDateTime", dir = "desc" }]
    Group = []

Raw string literal text - """ in string literals

var formatted_json = """
{
    "id" = "123"
    "SessionId" = ""
    "Sorting" = [{ "field" = "EventDateTime", "dir" = "desc" }]
    "Group" = []
}
""";

You can use .NET JsonSerializer from System.Text.Json namespace with specifying JsonSerializerOptions:

class Sample { public string Prop1 { get; set; } public string Prop2 { get; set; } }

var s = new Sample { Prop1 = "value1", Prop2 = "value2" };
Console.Write(JsonSerializer.Serialize(s, new JsonSerializerOptions { WriteIndented = true }))

Here's example using csharprepl:

UPDATE

Given example from question this could be achieved with:

dynamic sorting = new { field = "EventDateTime", dir = "desc" };
dynamic d = new { id = "123", SessionId = "", Sorting = new[] { sorting }, Group = Array.Empty<object>() };
Console.Write(JsonSerializer.Serialize(d, new JsonSerializerOptions { WriteIndented = true }));

And the output: