Authentication
This first task describes authenticating in AvaTax using the API, including the available authentication methods. It also provides helpful information about AvaTax’s two environments: Sandbox and Production.
If you know the authentication method you’re going to use, and you’re ready to authenticate, you can skip to the Ping the server section.
Part of the Marketplace integration guide. Open the full “Authentication” milestone on Avalara to see every page in this section.