fix: map WATI template params to positional keys (1, 2, ...) instead of named keys

app/channels/whatsapp.py

@@ -54,10 +54,26 @@ class WhatsAppChannel:
             "Content-Type": "application/json",
         }
 
-        parameters = [
-            {"name": str(k), "value": str(v)}
-            for k, v in template_data.items()
-        ]
+        # WATI templates use positional params named "1", "2", etc.
+        # If template_data contains positional keys ("1", "2", ...) use them directly.
+        # Otherwise map the canonical fields: otp → "1", expiry_minutes → "2".
+        has_positional = any(str(k).isdigit() for k in template_data)
+        if has_positional:
+            parameters = [
+                {"name": str(k), "value": str(v)}
+                for k, v in template_data.items()
+                if str(k).isdigit()
+            ]
+        else:
+            # Build positional params from canonical keys in order
+            ordered_keys = ["otp", "expiry_minutes", "merchant_name"]
+            positional = [
+                template_data[k] for k in ordered_keys if k in template_data and template_data[k] not in (None, "")
+            ]
+            parameters = [
+                {"name": str(i + 1), "value": str(v)}
+                for i, v in enumerate(positional)
+            ]
 
         url = f"{api_endpoint}/api/v1/sendTemplateMessage"
         payload = {