Serenade Pro requires WSL to run on Windows. On macOS and Linux, no other dependencies are required.
If you already have WSL installed, then you're all set! If not, you can follow these steps to install.
Open up PowerShell as an administrator and run:
dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart
Once Pro has been enabled on your account, Serenade Pro will download (and auto-update) when you start Serenade.
To switch to Pro, open Serenade, and then open the Settings window via the gear icon at top-right. Then, head to Server and select Serenade Pro.