C# Chromium browser whatsapp web send message using textbox

Question

I already follow the Chromium user guide, still doesn't work. Using my C# program, I want to send message or image via whatsapp web by cascading the textbox in my program with the message box of whatsapp. This is my code

using CefSharp;
using CefSharp.WinForms;
using System;
using System.Windows.Forms;


namespace ChromiumwithEditorWsWeb
{
public partial class Form1 : Form
{
    ChromiumWebBrowser browser;
    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        CefSettings settings = new CefSettings();
        Cef.Initialize(settings);

        browser = new ChromiumWebBrowser("http://web.whatsapp.com");
        browser.Dock = DockStyle.Fill;

        panel1.Controls.Add(browser);
    }

    private void buttonBack_Click(object sender, EventArgs e)
    {
        browser.Back();
    }

    private void buttonForward_Click(object sender, EventArgs e)
    {
        browser.Forward();
    }

    private void buttonReload_Click(object sender, EventArgs e)
    {
        browser.ShowDevTools();
    }

    private void buttonGo_Click(object sender, EventArgs e)
    {
        browser.Load(textBoxUrl.Text);
    }

    private void buttonPhoneNo_Click(object sender, EventArgs e)
    {


        browser.EvaluateScriptAsync("document.GetElementsByClass('jN-F5 copyable-text selectable-text').value = textBoxPhone.Text");
        browser.EvaluateScriptAsync("document.GetElementsByClass('_2S1VP copyable-text selectable-text').value = textBoxMessage.Text");

    }
}

}

Help it! Give suggestions for the best step.

Answer 1

        Clipboard.SetText(msg);
        Thread.Sleep(TimeSpan.FromSeconds(2));
        SendKeys.Send(msg); //SendKeys.SendWait("^{V}");
        Thread.Sleep(TimeSpan.FromSeconds(1));            
        SendKeys.SendWait("{ENTER}");

Not a good solution though, as it requires the windows to be on focus and this uses the clipboard. But it works !