ASP.NET Core Nhibernate ISession Dependency Injection error: Unable to resolve service for type while attempting to activate

I am creating a .Net Core (6.0) MVC application using NHibernate. When I try to build my solution I am getting an error:

System.AggregateException: 'Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: DiplomaWork.App.Services.IUserService Lifetime: Scoped ImplementationType: DiplomaWork.App.Services.UserService': Unable to resolve service for type 'NHibernate.ISession' while attempting to activate 'DiplomaWork.App.Services.UserService'.)'

and two inner errors ( InvalidOperationException) related to ISession. Please find below my

Program.cs

using DiplomaWork.App;
using DiplomaWork.App.Services;
using Microsoft.IdentityModel.Tokens;
using System.Text;

var builder = WebApplication.CreateBuilder(args);

var configValue = builder.Configuration;
var authenticationSettings = new AuthenticationSettings();

configValue.GetSection("Authentication").Bind(authenticationSettings);

// Add services to the container.
builder.Services.AddControllersWithViews();
builder.Services.AddScoped<IUserService, UserService>();
builder.Services.AddSingleton(authenticationSettings);
builder.Services.AddAuthentication(option =>
{
    option.DefaultAuthenticateScheme = "Bearer";
    option.DefaultScheme = "Bearer";
    option.DefaultChallengeScheme = "Bearer";
}).AddJwtBearer(cfg =>
{
    cfg.RequireHttpsMetadata = false;
    cfg.SaveToken = true;
    cfg.TokenValidationParameters = new TokenValidationParameters
    {
        ValidIssuer = authenticationSettings.JwtIssuer,
        ValidAudience = authenticationSettings.JwtIssuer,
        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(authenticationSettings.JwtKey))
    };
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseAuthentication();
app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();
app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

UserService.cs

using ISession = NHibernate.ISession;
using AutoMapper;
using DiplomaWork.App.Models;
using System.Security.Claims;
using Microsoft.IdentityModel.Tokens;
using System.Text;
using System.IdentityModel.Tokens.Jwt;

namespace DiplomaWork.App.Services
{
    public class UserService : IUserService
    {
        private readonly ISession _session;
        private readonly IMapper _mapper;
        private readonly AuthenticationSettings _authenticationSettings;

        public UserService(ISession session, IMapper mapper, AuthenticationSettings authenticationSettings)
        {
            _session = session;
            _mapper = mapper;
            _authenticationSettings = authenticationSettings;
        }

        public string GenerateJwt(LoginDto dto)
        {
            var user = _session.Query<Entities.User>().FirstOrDefault(x => x.Login == dto.Login);

            if (user == null)
            {
                throw new Exception("Invalid login or password");
            }

            if (dto.Password != user.Password)
            {
                throw new Exception("Invalid login or password");
            }

            var claims = new List<Claim>()
            {
                new Claim(ClaimTypes.NameIdentifier, user.UserId.ToString()),
                new Claim(ClaimTypes.Name, $"{user.Firstname}"),
            };

            var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_authenticationSettings.JwtKey));
            var credentials = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
            var expires = DateTime.Now.AddMinutes(_authenticationSettings.JwtExpireMinutes);

            var token = new JwtSecurityToken(_authenticationSettings.JwtIssuer,
                _authenticationSettings.JwtIssuer,
                claims,
                expires: expires,
                signingCredentials: credentials);
            var tokenHandler = new JwtSecurityTokenHandler();

            return tokenHandler.WriteToken(token);
        }

        public User GetUserById(long userId)
        {
            var userEntity = _session.Get<Entities.User>(userId);
            if (userEntity == null) throw new Exception("User not found");

            var user = _mapper.Map<User>(userEntity);

            return user;
        }
    }
}

By the way, I cannot find fresh documentation for NHibernate so would be grateful for any links offering free help.