How can I send whats app message from VB.NET

<pre> Try
            Dim web As New WebBrowser

           
            web.Navigate("whatsapp://send?phone=" & TextBox3.Text & "&text=" & TextBox2.Text.Replace(" ", "+") & "")
           
            Timer1.Start()
        Catch ex As Exception
            Timer1.Stop()
        End Try

    End Sub

  
    Dim sec As Integer = 0
    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        sec += 1
        If sec = 5 Then
            SendKeys.Send("{ENTER}")
            Timer1.Stop()
            sec = 0
        End If
    End Sub