Web API App-Only with Graph API

get-graph-api-result.cs

[HttpGet]
public async Task<IActionResult> Get()
{
  ...

  try
  {
    using (var client = new HttpClient())
    {
      client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", authResult.AccessToken);
      client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
      var url = $"{this._graphUrl}/{this._version}/{Organisation}";

      var resultAsString = await client.GetStringAsync(url);

      var organisation = JObject.Parse(resultAsString);
      var result = new JsonResult(organisation);
      return result;
    }
  }
  catch (Exception ex)
  {
    var result = new JsonResult(ex);
    return result;
  }
}