Why nothing is passed to the WEB API METHOD

private async void TakePhoto_Clicked(object sender, EventArgs e)
 {
     var file = await MediaPicker.CapturePhotoAsync();
     var content = new MultipartFormDataContent();
     content.Add(new StreamContent(await file.OpenReadAsync()), "file", file.FileName);
     string url = "https://10.0.2.2:7254/api/GetData/Upload/";
     client.BaseAddress = new Uri(url);       
     var response = await client.PostAsync("", content);
     if (response.IsSuccessStatusCode)
           
  }

Web API
[HttpPost]
[Route("Upload")]
public async Task<string> Upload(  List <IFormFile> files)    
{
    try
    {
        foreach (var formFile in files)
        {
           if (formFile.Length > 0)
           {
              var fileName =  formFile.FileName.Split('\\').LastOrDefault().Split('/').LastOrDefault();
              var filePath = Path.Combine(Directory.GetCurrentDirectory(), "imagenes", fileName);
                       
               using (var stream = System.IO.File.Create(filePath))
               {
                  await formFile.CopyToAsync(stream);
               }