To download your product, you must first register your serial key.
If you are a new customer of Synapse Audio Software, create a new service account here: https://www.synapse-audio.com/service-create.html
If you already have a service account, register your new software to your existing account here: https://www.synapse-audio.com/support.html.
Go to the "Registrations" area, then click "Register new serial number". Now proceed to the "Downloads" area and your product downloads will appear.