You can test C#/.NET with jupyter notebook. If you want to import some nuget packages from online. Just add like this:

//#r "nuget: Newtonsoft.Json"

I wrote a code that simply expresses the period I studied '.Net'.

using Newtonsoft.Json.Linq;

DateTime begin = new(2016,3,1);
DateTime now = DateTime.Now;
var years = Enumerable.Range(begin.Year, now.Year-begin.Year+1);

JObject json = new()
{
    ["content"] = ".NET study",
    ["years"] = JArray.FromObject(years),
};

Console.WriteLine($"{nameof(json)}:\n{json}");

json:
{
  "content": ".NET study",
  "years": [
    2016,
    2017,
    2018,
    2019,
    2020,
    2021,
    2022
  ]
}