Automation libraries can't find file

Question

I want to write an automation desktop app
I used three frameworks by using C# language

1. Appium
2. FlaUI
3. Winium

My windows application start with auto updating when to start.

First using Appium it throw message is

The system cannot find the file specifiled

Code

        var appiumOptions = new AppiumOptions();

        appiumOptions.AddAdditionalCapability("app", @"C:\\Testapp\TestAutoUpdateAppWinform.exe");
        appiumOptions.AddAdditionalCapability("deviceName", "WindowsPC");
        appiumOptions.AddAdditionalCapability("platformName", "Windows");

        var _driver = new WindowsDriver<WindowsElement>(new Uri("http://127.0.0.1:4723"), appiumOptions);

        _driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(5);

Second using FlaUI it throw message is

The system cannot find the file specifiled

Code

        var app = FlaUI.Core.Application.Launch(@"C:\\Testapp\TestAutoUpdateAppWinform.exe");
        using (var automation = new UIA2Automation())
        {
            Thread.Sleep(TimeSpan.FromSeconds(10));
            //await Task.Delay(TimeSpan.FromSeconds(10));
            //Task.Delay(TimeSpan.FromSeconds(2));
            var window = app.GetMainWindow(automation);

            string title = window.Title;

            var usernameTxt = window.FindFirstDescendant(cf => cf.ByAutomationId("330584")).AsTextBox();
            usernameTxt.Text = "sometext";



            window.Close();

        }

Third using Winium does work

Code

        var dc = new DesiredCapabilities();
        dc.SetCapability("app", @"C:\\Testapp\TestAutoUpdateAppWinform.exe");
        var driver = new RemoteWebDriver(new Uri("http://localhost:9999"), dc);

        //string title = driver.Title;
        //Console.WriteLine(title);

        var _ = driver.FindElementById("132516");

and I do not want to use Winium because it has less example.
I want to use FlaUI and Appium because it has more example and easy to use.