The primary documentation is the PDF included inside the Asset Store Package which you downloaded when you bought/upgraded/installed the asset – this is always up to date. You can see/download a recent version below (PDF Manual).
The plugin also contains many demo scenes, in the “Demo Scenes” subfolder – some of these are described in the PDF in more detail – but feel free to play with them, use/modify the scripts etc.
The v2 API docs are now offline – I’m rewriting them for SAPv3. If you still need a copy of the v2 API, please email support @ snapandplug.com and I’ll send you the archived copy.
Online (written) tutorials
There are also some old online tutorials (2016) here (but you’re better off using the PDF manual described above):