How to code Blazor Server upload saveUrl with minimum web API?

[Jay]

I'm trying to use the TelerikUpload control in a Blazor server project. I created a Blazor server project from the Telerik template.

I'm trying to use only minimum web API for the upload endpoints. I haven't added controllers or routing to the configuration.

The issue is that I'm getting a 400 error when I use the MapPost().  I've  tried many different variations for the post action parameters.

 app.MapPost("upload/save",  async (IFormFile files) =>
 {       
        if (files != null)
        {                  
            var physicalPath = Path.Combine("D:\\Source\\repos\\BlazorVPMS\\BlazorVPMS", "Upload/", files.FileName);
            logger.Debug(physicalPath);

            using (var fileStream = new FileStream(physicalPath, FileMode.Create))
            {
                await files.CopyToAsync(fileStream);
            }
        }
    });

The only post method that works is this, after I added a form tag to the html.  

 app.MapPost("upload/save", async (IConfiguration config, HttpRequest request) =>
    {
        var files = request.Form.Files.First();
        if (files != null)
        {             
            //string path = config["StoredFilesPath"];
            var physicalPath = Path.Combine("D:\\Source\\repos\\BlazorVPMS\\BlazorVPMS", "Upload/", files.FileName);
            logger.Debug(physicalPath);

            using (var fileStream = new FileStream(physicalPath, FileMode.Create))
            {
                await files.CopyToAsync(fileStream);
            }
        }
    });

What do need to do to make this work with just using the IFormFile? Do I need to just add an API controller and routing to my configure and not use the minimum API?

[Dimo]

Jay, probably this SO thread will throw some light on the case.

[Jay]

Thank you, yes that StackOverflow thread helps. I finally added controllers to the project and have it working.