Hi again 
That version of CertSage is rather old. The staging environment is used for testing your CertSage installation to be sure it can correctly communicate with Let's Encrypt. By using the staging environment to test, you avoid the much stricter limits of the production environment should you encounter an issue that requires retesting to confirm resolution.
You should update to the latest version of CertSage, which is much easier to use and has much more detailed instructions: