diff --git a/backend/public/debug-chatbot.php b/backend/public/debug-chatbot.php
index 80013c7..58125ca 100644
--- a/backend/public/debug-chatbot.php
+++ b/backend/public/debug-chatbot.php
@@ -27,6 +27,27 @@ $healthHttpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
 $healthError = curl_error($ch);
 curl_close($ch);
 
+// Test message sending endpoint to see what response it gives (404, 403, etc)
+$sendUrl = $gatewayUrl . '/api/messages/send';
+$payload = json_encode([
+    'session_key' => 'mock_test_session',
+    'phone' => '1234567890',
+    'message' => 'test'
+]);
+$ch = curl_init($sendUrl);
+curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+curl_setopt($ch, CURLOPT_POST, true);
+curl_setopt($ch, CURLOPT_POSTFIELDS, $payload);
+curl_setopt($ch, CURLOPT_HTTPHEADER, [
+    'Content-Type: application/json',
+    'X-Webhook-Secret: ' . getenv('WEBHOOK_SECRET')
+]);
+curl_setopt($ch, CURLOPT_TIMEOUT, 5);
+$sendResponse = curl_exec($ch);
+$sendHttpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+$sendError = curl_error($ch);
+curl_close($ch);
+
 echo json_encode([
     'env' => [
         'WHATSAPP_GATEWAY_URL' => getenv('WHATSAPP_GATEWAY_URL'),
@@ -39,6 +60,12 @@ echo json_encode([
         'response' => json_decode($healthResponse, true) ?: $healthResponse,
         'error' => $healthError
     ],
+    'gateway_send_test' => [
+        'url' => $sendUrl,
+        'http_code' => $sendHttpCode,
+        'response' => json_decode($sendResponse, true) ?: $sendResponse,
+        'error' => $sendError
+    ],
     'chatbot_rules' => $rules,
     'messages_log' => $logs,
     'whatsapp_sessions' => $sessions