c # – Save list information in MVC txt

Good afternoon guys, since I am new to mvc I would like to receive help from you if possible, I am trying to get some data from my list, add it to a txt file and save it to my machine, what happens is that the file is generated in my c: however I can't write the information coming from my list to the file, could you help me if possible. Here is an example from my controller.

        public IActionResult Exportar(DateTime dateTime, DateTime dateTimeFinal)

            var Layout = _context.RegistroDePontos.Where(e => e.data >= dateTime && e.data <= dateTimeFinal).ToList();
            string nomeArquivo = @"C:" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".txt";
            StreamWriter writer = new StreamWriter(nomeArquivo, true);
            for(int i = 0; i < Layout.Count; i++)

            return View("Exportar",Layout);