fix whastapp and add unit test

lib/callmebot_whatsapp_service.ts

@@ -8,20 +8,24 @@
  *   https://www.callmebot.com/blog/free-api-whatsapp-messages/
  * - Make sure your Google Apps Script project has the necessary permissions (like UrlFetch) enabled.
  */
-class WhatsAppAPI {
+class CallMeBotWhatsAppAPI {
     /**
      * Sends a WhatsApp text message to the provided phone number.
      *
-     * @param phoneNumber The recipient's phone number in international format (e.g., +6281854378145).
      * @param message The text message to be sent.
      * @throws Error if the API key is not found in script properties or an error occurs during the API request.
      */
-    public static async sendMessage(phoneNumber: string, message: string): Promise<void> {
+    public static async sendMessage(message: string): Promise<void> {
         const apiKey = PropertiesService.getScriptProperties().getProperty('call_me_bot_api_key');
         if (!apiKey) {
             throw new Error('API key not found in script properties. Please set the "call_me_bot_api_key" property.');
         }
 
+        const targetPhoneNumber = PropertiesService.getScriptProperties().getProperty('call_me_bot_target_phone');
+        if (!targetPhoneNumber) {
+            throw new Error('Target phone number not found in script properties. Please set the "call_me_bot_target_phone" property.');
+        }
+
         const url = `https://api.callmebot.com/whatsapp.php?phone=${phoneNumber}&text=${message}&apikey=${apiKey}`;
 
         try {

test/test_send_whastapp.ts

@@ -0,0 +1,3 @@
+function TestSendWhatsapp() {
+    CallMeBotWhatsAppAPI.sendMessage("Test Send Whatsapp");
+}