Need a feature to integrate transaction level sales from different POS systems (Wix, Square and Etsy) and the tool determine what sales and use tax due will be each month

You may utilize an inventory management app as the connector. Intuit has acquired it recently.

https:// go.tradegecko.com/register?code=fiat-lux

You will need another connector to integrate Wix

https://www. integromat.com/?pc=quickbooks

then you may explore this AST Filing & Reporting app to integrate with your QBO account

https:// taxjar.grsm.io/mytax