add missing file

http-api/app/routes/billing/__init__.py

@@ -0,0 +1,27 @@
+from datetime import date
+from typing import Annotated
+
+from aws_lambda_powertools.event_handler.api_gateway import Router
+from aws_lambda_powertools.event_handler.openapi.params import Path, Query
+from layercake.dynamodb import DynamoDBPersistenceLayer, KeyPair
+
+from boto3clients import dynamodb_client
+from config import ORDER_TABLE
+
+router = Router()
+order_layer = DynamoDBPersistenceLayer(ORDER_TABLE, dynamodb_client)
+
+
+@router.get('/<id>', compress=True, tags=['Billing'])
+def get_billing(
+    id: Annotated[str, Path()],
+    start_date: Annotated[date, Query()],
+    end_date: Annotated[date, Query()],
+):
+    result = order_layer.collection.query(
+        KeyPair(
+            pk=f'BILLING#ORG#{id}',
+            sk=f'START#{start_date}#END#{end_date}',
+        )
+    )
+    return result