The Avalara AvaTax release schedule includes a preview period. During which time, the latest software is available for integration testing in the AvaTax Sandbox Environment two weeks before launching to production. If your engineering team would like a sandbox account for integration testing purposes:

Development and Solutions Partners (DSP), please contact your Business Development Manager.
Avalara customers, please contact your Customer Account Manager or open a support ticket.

Fixes and improvements

AvaTax API Enhancements:

Updated some Marketplace content error messages to make them more user friendly.
Fixed an issue with creating Tax Notices in the SBX environment.
Updated the documentation for the GetTransactionById API

Returns API Enhancements:

Fixed an issue when trying to expire Paper returns in Avatax Update.

ENVIRONMENT	URL	RELEASE DATE
Sandbox	https://sandbox-rest.avatax.com	2022-02-10
Production	https://rest.avatax.com	2022-02-17