set a flash trigger to enable spree's google analytics ecommerce trackin...

To enable google analytics ecommerce tracking for completed orders you have to set the flash trigger. Like in the spree gem checkout_controller. https://github.com/spree/spree/blob/42f8b63cb898c44b88964e4bfcfe3eddef646115/frontend/app/controllers/spree/checkout_controller.rb#L38