AvaTax Admin covers some options for using AvaTax for automatic sales tax lookups.
Employee Access lets you set Show AvaTax Lookup to display the AvaTax Lookup button and AvaTax Response. It is not needed for the automatic lookups when saving.
Employees Search lets you Add (+) a Column for Show AvaTax Lookup to see which Employees have this enabled, and to select one or more, click Update and change them.
AvaTax Response is the complete response from AvaTax with all results or any error.
AvaTax Reponse only appears when an Employee has Show AvaTax Lookup enabled. AvaTax Response shows on the Shipping tab of a looked-up Quote, Order, or Invoice.
AvaTax Lookup happens automatically when you save any Quote, Order, or Invoice.
There is also an option to show the AvaTax Lookup button the Expanded tab of each. This is enabled per Employee for those that a need an instant answer to Tax and Total.