问如何设置Azure应用程序的权限，以便应用程序可以访问站点及其驱动器？

EN

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace GraphAPITest
{
    class Program
    {
        static void Main(string[] args)
        {
            var accessToken = GetAccessToken().GetAwaiter().GetResult();
            Console.WriteLine(GetSite(accessToken).GetAwaiter().GetResult());
        }



        public static async Task<string> GetAccessToken()
        {

            using (var client = new HttpClient())
            {
                var clientId = "<app id>"; 
                var clientSecret = "<secret>";
                var tenant = "<your tenant name/id>";

                var scope = @"https://graph.microsoft.com/.default";
                var tokenUrl = @"https://login.microsoftonline.com/"+ tenant + "/oauth2/v2.0/token";
                client.BaseAddress = new Uri(tokenUrl);
                // We want the response to be JSON.
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                // Build up the data to POST.
                List<KeyValuePair<string, string>> postData = new List<KeyValuePair<string, string>>();
                postData.Add(new KeyValuePair<string, string>("grant_type", "client_credentials"));
                postData.Add(new KeyValuePair<string, string>("client_id", clientId));
                postData.Add(new KeyValuePair<string, string>("client_secret", clientSecret));
                postData.Add(new KeyValuePair<string, string>("scope", scope));
                FormUrlEncodedContent requestBody = new FormUrlEncodedContent(postData);
                //Request Token
                var request = await client.PostAsync(tokenUrl, requestBody).ConfigureAwait(false);
                var response = await request.Content.ReadAsStringAsync();
                var responseData = JsonConvert.DeserializeObject(response);
                //Return Token
                return ((dynamic)responseData).access_token;
            }
        }

        public static async Task<dynamic> GetSite(string accessToken)
        {

            using (var client = new HttpClient())
            {
                var baseUrl = "https://graph.microsoft.com/v1.0/";
                client.BaseAddress = new Uri(baseUrl);
                client.DefaultRequestHeaders.Accept.Clear();
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                // Add the Authorization header with the AccessToken.
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + accessToken);
                // create the URL string.
                string url = string.Format("{0}sites/root/", baseUrl);
                 

   // make the request
                HttpResponseMessage response = await client.GetAsync(url).ConfigureAwait(false);
                // parse the response and return the data.
                string jsonString = await response.Content.ReadAsStringAsync();
                object responseData = JsonConvert.DeserializeObject(jsonString);
                return (dynamic)responseData;
            }
        }
    }

    
}