Send SMS with 🔷 VB.net

// 1 — PRIMARY — use this
https://www.isms.com.my/isms_send_all_id.php
// 2 — Mirror — backup only
https://smtpapi2.vocotext.com/isms_send_all_id.php
// 3 — Mirror — backup only
https://smtpapi.vocotext.com/isms_send_all_id.php
// 4 — Mirror — backup only
https://ww3.isms.com.my/isms_send_all_id.php

Imports System.Net.Http
Imports System.Collections.Generic

Module IsmsSender

    ' Reuse HttpClient — do not create per request
    Private ReadOnly _client As New HttpClient()

    Async Function SendSmsAsync(mobile As String, message As String) As Task(Of String)

        Dim payload = New Dictionary(Of String, String) From {
            {"un",         "your_username"},   ' iSMS username
            {"pwd",        "your_password"},   ' iSMS password
            {"dstno",      mobile},            ' e.g. "601X-XXXXXXX"
            {"msg",        message},
            {"type",       "1"},               ' 1 = ASCII, 2 = Unicode
            {"agreedterm", "YES"},
            {"sendid",     "MyBrand"}          ' Optional, max 11 chars
        }

        Dim content  = New FormUrlEncodedContent(payload)
        Dim response = Await _client.PostAsync(
            "https://www.isms.com.my/isms_send_all_id.php", content)

        Return Await response.Content.ReadAsStringAsync()
    End Function

    Sub Main()
        Dim result = SendSmsAsync("601X-XXXXXXX", "Hello from iSMS!").Result

        If result.StartsWith("2000") Then
            Dim trxId = result.Split(":"c)(1)
            Console.WriteLine("SMS sent! Transaction ID: " & trxId)
        Else
            Console.WriteLine("Failed: " & result)
        End If
    End Sub

End Module