I try to connect to a database using MySql.Data but it doesn’t work. What did i do wrong?

                private List<Car> cars;
        private MySqlConnection conn;
        private static uint DB_PORT = 3306;
        private static string DB_HOST="localhost";
        private static string DB_USER = "root";
        private static string DB_PASSWORD = "";
        private static string DB_DATABASE = "database";

        public ...()
        {
            cars = GetCars();
                }

public List<Car> GetCars()
        {
            List<Car> cars = new List<Car>();
            MySqlConnectionStringBuilder builder = new MySqlConnectionStringBuilder();
            builder.Password = DB_PASSWORD;
            builder.Port = DB_PORT;
            builder.Database = DB_DATABASE;
            builder.UserID = DB_USER;
            builder.Server= DB_HOST;
            conn = new MySqlConnection(builder.ConnectionString);
            conn.Open();

            string sql = "SELECT * FROM cars";
            MySqlCommand cmd=new MySqlCommand(sql, conn);
            
            MySqlDataReader reader = cmd.ExecuteReader();

            while (reader.Read())
            {
                int id = reader.GetInt32("id");
                string license_plate_number = reader.GetString("license_plate_number");
                string brand = reader.GetString("brand");
                string model=reader.GetString("model");
                int daily_cost = reader.GetInt32("daily_cost");

                Car car=new Car(id, license_plate_number, brand, model,daily_cost);
                cars.Add(car);
            }

            return cars;
        }

It doesn’t send any error codes, but it doesn’t connect to the database succesfully because the list has no elements.