Serial number need when i start the 3 day trial verision

I can't use the serum shit that you guys sell beacuse it asks me to put in a serial number. And guess what. When i go to the link i referrs me to, there is no serial number anywhere. No good explination anywhere aswell. Uninstalling right away:)

You should not be asked for a serial. However the Splice app is required Make sure you are signed in to the Splice application.
https://splice.com/download