Power BI REST API authentication

I solved the problem by just using RestSharp and Newtonsoft.Json. I created a ASP.Net Core API project and this is the code for my controller.

using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc;
using RestSharp;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json;

namespace PortalAPI.Controllers
{
    [Produces("application/json")]
    [Route("api/Reports")]
    public class ReportsController : Controller
    {
        private static string PBI_REST_API_URL = "http://myserver/reports/api/v2.0";

        private static string PBI_REPORTS_URL = "http://myserver/reports/powerbi";

        // GET api/values
        [HttpGet]
        public string Get()
        {
            var client = new RestClient(PBI_REST_API_URL)
            {
                Authenticator = new RestSharp.Authenticators.NtlmAuthenticator()
            };
            RestRequest reportsRequest = new RestRequest("/CatalogItems", Method.GET);

            var response = client.Execute(reportsRequest);

            var svar = JObject.Parse(response.Content);

            var reportList = (JArray)svar["value"];

            var resultReportList = new List<Report>();

            foreach(JObject report in reportList)
            {
                if (((string)report["@odata.type"]).Equals("#Model.PowerBIReport"))
                {
                    resultReportList.Add(new Report { Name = (string)report["Name"], Path = PBI_REPORTS_URL + (string)report["Path"] });
                }
            }

            return JsonConvert.SerializeObject(resultReportList); ;
        }
    }

    public class Report
    {
        public string Name { get; set; }
        public string Path { get; set; }
    }
}

Since I dont need all values from the returnd JSON it was very conveniant to just pick the stuff I needed with Newtonsoft.Json. The service will have to be run with an account that has access to PBI Report Server. Hope this helps someone.