first upload all files

Modules/Checkout/Resources/lang/en/mail.php

@@ -0,0 +1,8 @@
+<?php
+
+return [
+    'new_order_subject' => 'A new order has been placed',
+    'new_order_text' => 'A new order has been placed. The order id is #:order_id.',
+    'view_order' => 'View Order',
+    'if_you\’re_having_trouble' => 'If you’re having trouble clicking the "View Order" button, copy and paste the URL below into your web browser:',
+];