Cosmos token controllerr

CosmosController.cs

using System.Threading.Tasks;
using IConfiguration = Microsoft.Extensions.Configuration.IConfiguration;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Cosmos;
using BlazorCosmosWasm.Shared;
using Microsoft.AspNetCore.Identity;
using BlazorCosmosWasm.Server.Models;

namespace BlazorCosmosWasm.Server.Controllers
{
    [Authorize]
    [Route("api/[controller]")]
    [ApiController]
    public class CosmosController : ControllerBase
    {
        private readonly UserManager<ApplicationUser> Manager;

        public CosmosController(IConfiguration config, UserManager<ApplicationUser> manager)
        {
            Config = config;
            Manager = manager;
            Client = config.CreateCosmosClientFromConfig();
       }

        private CosmosClient Client { get; }
        public IConfiguration Config { get; set; }

        [HttpGet]
        public async Task<IActionResult> Get()
        {
            var user = await User.GetEmailAsync(Manager);
            if (user == null)
            {
                return NotFound();
            }
            var db = Client.GetDatabase(BlogContext.DatabaseName);
            var container = db.GetContainer(nameof(BlogContext));
            var cosmosUser = db.GetUser(user);
            var permissionId = $"Permission-{user}-blogs";
            await cosmosUser.UpsertPermissionAsync(new PermissionProperties(
                        id: permissionId,
                        permissionMode: PermissionMode.Read,
                        container: container));
            var token = await cosmosUser.GetPermission(permissionId).ReadAsync();
            return Ok(
                new CosmosCredentials
                {
                    EndPoint = Client.Endpoint.ToString(),
                    Key = token.Resource.Token
                });
        }
    }
}