We do not recommend using checkout redirect to process order details into a fulfilment system. Our supported platforms do that automatically, and custom integrations can use the Order Callback API to securely process orders.
Google Analytics Ecommerce tracking
This example uses PHP scripting. Other languages will need to adapt for different methods of accessing HTTP request variables.This example may be different if using the newer Universal Analytics style.
Generally the same variables from the Order Callback API are available to Checkout Redirect.
Testing your checkout redirect landing page