How do I find which version of taxation my account is using?

In the Fusebill Admin UI, Navigate to Settings > Financial > Taxes

If taxation is not enabled, it will display information on which taxation platforms are available you would like to use. 

Information on how to configure taxation can be found here Configuring Taxes

Basic Taxation:

The basic taxation module will display a list of your currently configured taxes as well as options to configure additional tax rules. 

Advanced Taxation:

If Advanced Taxation is configured in your account, it will display a list of the active Nexus jurisdictions:

Avalara Direct:

If Avalara Direct is configured for your account, then this detailed screen will appear: