add submission order param

app/controllers/api/submissions_controller.rb

@@ -67,7 +67,7 @@ module Api
             user: current_user,
             source: :api,
             mark_as_sent: is_send_email,
-            submitters_order: params[:submitters_order] || 'preserved',
+            submitters_order: params[:submitters_order] || params[:order] || 'preserved',
             submissions_attrs:
           )
         end