Confirm that your email address with Splice is correctly tied to an email address you can login to.
From the Splice Desktop App install Arturia Software Center
If you're not seeing Arturia Software Center in the Tools section of the Splice app, log out and back into the Splice app
Check your email for a message from Arturia to setup your Arturia account
Log in to the Arturia Software Center and install your Arturia plugin
Once signed into Arturia Software Center, you must “activate” the plugin. To do so click on the “Activate” button.
Sync button on Arturia Software Center will retrieve any updated license info from your Arturia account.