I have this error making a web app that gets info from an API, both made with ASP.NET Core MVC.

{StatusCode: 400, ReasonPhrase: 'Bad Request', Version: 1.1, Content: System.Net.Http.HttpConnectionResponseContent, Headers:
{
  Date: Mon, 29 Apr 2024 07:42:05 GMT
  Server: Kestrel
  Transfer-Encoding: chunked
  Content-Type: application/problem+json; charset=utf-8
}}

I have it in this part of the code, in the API Service class:

        public async Task<bool> Guardar2(BACKUP_IPADS objeto2)
        {
            bool respuesta = false;

            await Autenticar();

            var cliente = new HttpClient();
            cliente.BaseAddress = new Uri(_baseurl);
            var content = new StringContent(JsonConvert.SerializeObject(objeto2), Encoding.UTF8, "application/json");
            var response = await cliente.PostAsync("api/BACKUP_IPADS/Entregar_Ipad/", content);

            if (response.IsSuccessStatusCode)
            {

                respuesta = true;

            }

            return respuesta;
        }

it returns false

this is the part of the controller:

[HttpPost]
        public async Task<IActionResult> Entregar(BACKUP_IPADS ob_backup)
        {
            bool respuesta;

            respuesta = await _servicioAPI.Guardar2(ob_backup);


            if (respuesta)
            {
                return RedirectToAction("Index2");
            }
            else
            {
                return NoContent();
            }
        }

this is the part of the button in the html:

                <div style="margin-right: 4px;">
                    <form asp-action="Entregar" asp-controller="Home" method="post">
                        <button type="submit" class="btn btn-success btn-sm" style="border-radius: 5px;">Entregar</button>
                    </form>
                </div>