In rare occasions, the Shopify APP and authentication may get in conflict. In case you have already re-authenticated, and still facing the ‘Authentication failed’ message, resetting the connection will eventually solve the problem.
The message format for the error.
Steps to completely reset the connection with Shopify
Delete Supermetrics app from Shopify User Interface
Log out the Shopify data source from https://team.supermetrics.com/token-management
Remove the Shopify data source in Data Studio by following this article https://support.supermetrics.com/support/solutions/articles/19000090785-how-do-i-completely-remove-a-data-source-
Revoke access from connector gallery in DS at https://datastudio.google.com/datasources/create
Re-select the connector in the gallery and complete authentication
I tried everything and it still has the error!
Please then submit a private ticket to Supermetrics Support for further assistance. Please note in the ticket that you've completed all the steps in this article so we know you already tried these.