Getting HTML file from cefsharp browser

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    browser.ViewSource()
End Sub

Imports CefSharp.WinForms
Imports CefSharp

Public Class Form1

    Private WithEvents browser As ChromiumWebBrowser

    Public Sub New()
        InitializeComponent()

        Dim settings As New CefSettings
        CefSharp.Cef.Initialize(settings)

        browser = New ChromiumWebBrowser("url") With {
            .Dock = DockStyle.Fill
        }
        Panel1.Controls.Add(browser)
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        browser.ViewSource()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        browser.Load(TextBox1.Text)
    End Sub

End Class