How to get instance of EditText in Appium - C#

I able to open my app successfully using Appium C#. Now on loginPage I want to get EditText so that I can fill userName.

I have tried many ways but all throwing or other issues. This is my code

public class UnitTest1
{
    private AndroidDriver<AndroidElement> driver;
    private DesiredCapabilities capabilities;

    [SetUp]
    public void InItDriver()
    {
        capabilities = new DesiredCapabilities();          
        capabilities.SetCapability("deviceName", "ZZ2222HMLF");
       //capabilities.SetCapability("[platformName", "Android");
        capabilities.SetCapability("noReset", true);
        capabilities.SetCapability("autoGrantPermissions", "true");
        capabilities.SetCapability("appPackage", "com.sisapp.in.lgm");
        capabilities.SetCapability("automationName", "UiAutomator2");
        capabilities.SetCapability("appActivity", "md5b1afd03e09ce5243fd0287b176ff38ea.SplashActivity");
        driver = new AndroidDriver<AndroidElement>(new Uri("http://127.0.0.1:4723/wd/hub"), capabilities);
        //driver = new AndroidDriver<AndroidElement>(new Uri("https:127.0.0.1:4723/wd/hub"), capabilities);
    }
    [Test]
    public void Test1()
    {
       AndroidElement textView = driver.FindElementById("input_name");      
       textView.SendKeys("ak@ct");
       Assert.IsNotNull(driver);
       System.Threading.Thread.Sleep(2000);
    }

    [TearDown]
    public void CloseTest()
    {
        //driver.Quit();
    }
}

Throwing exception

Message: OpenQA.Selenium.InvalidSelectorException : Locator Strategy 'css selector' is not supported for this session

How can I solve this issue?