I am able to ‘create’ a file on google-Drive using the below code however I have noticed the files have 0 bytes. I am using a Service Account which is Editor. I am using the Radzen Upload Control.

<RadzenUpload Url="upload/single" Progress=@(args => TrackProgress(args, "Single file upload")) class="w-100" InputAttributes="@(new Dictionary<string,object>(){ { "aria-label", "select file" }})"> </RadzenUpload>

The controller used to receive the file

[DisableRequestSizeLimit]
public partial class UploadController : Controller
{
    private readonly IWebHostEnvironment environment;
    private readonly GoogleDriveService _googleDriveService;

    public UploadController(IWebHostEnvironment environment, GoogleDriveService googleDriveService)
    {
        this.environment = environment;
        _googleDriveService = googleDriveService;           
    }


    // Single file upload
    [HttpPost("upload/volunteer")]
    public IActionResult Volunteer(IFormFile file)
    {
        try
        {
            _googleDriveService.UploadFile(file, this.environment);       

            return StatusCode(200, file.FileName);
        }
        catch (Exception ex)
        {
            return StatusCode(500, ex.Message);
        }
    }
}

My Service for Working with Google Drive

public string UploadFile(IFormFile File, IWebHostEnvironment environment)
{
    string uploadedFileId = "";

    string RootFolderId = "xxxxxxxxxxxxxxxxxxxxxxxx";   \Target Folder

    var service = Auth();

    try
    {
        FilesResource.CreateMediaUpload request;
        using (var stream = new FileStream(Path.Combine(environment.WebRootPath, File.FileName), FileMode.Create))
        {
            using (MemoryStream memoryStream = new MemoryStream())
            {
                stream.CopyTo(memoryStream);
                Google.Apis.Drive.v3.Data.File fileMetadata = new Google.Apis.Drive.v3.Data.File
                {
                    Name = File.FileName,
                    Parents = new List<string> { RootFolderId }
                };
                request = service.Files.Create(fileMetadata, memoryStream, File.ContentType);
                request.Fields = "id";
                request.SupportsTeamDrives = true;
                request.SupportsAllDrives = true;
                request.Upload();
            }
        }
        Google.Apis.Drive.v3.Data.File file = request.ResponseBody;
        uploadedFileId = file.Id;

        return uploadedFileId;
    }
    catch (Exception ex)
    {
        var x = ex;
    }

    return uploadedFileId;
}


public DriveService Auth()
{
    var credential = GoogleCredential.FromFile(
            Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", PathToServiceAccountKeyFile))
            .CreateScoped(DriveService.ScopeConstants.Drive);

    // Create the  Drive service.
    DriveService service = new DriveService(new BaseClientService.Initializer()
    {
        HttpClientInitializer = credential
    });

    return service;
}

My Auth code for the API

public DriveService Auth()
{
    // Load the Service account credentials and define the scope of its access.
    var credential = GoogleCredential.FromFile(
                    Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", PathToServiceAccountKeyFile))
                    .CreateScoped(DriveService.ScopeConstants.Drive);

    // Create the  Drive service.
    DriveService service = new DriveService(new BaseClientService.Initializer()
    {
        HttpClientInitializer = credential
    });

    return service;
}

The upload Looks as though it works, a file is created in Google Drive at the right location, there is just no Content (0 bytes)