If you are getting the error “Invalid auth/bad request (got a 401, expectedHTTP/1.1 20X or a redirect)” in XPS when using Quickbooks Online you will need to reconnect the integration.
Click the Dashboard tab.
Scroll to the bottom to Ecommerce Integrations, and select your Quickbooks Online integration.
At the bottom select "Reconnect Integration".
This will bring you to the Quickbooks Online page. A page will pop up asking for your authorization to securely share your data with RSIS/ XPS /Webship. Click "Authorize" located in the bottom right corner. You will be redirected to Quickbooks and it may ask you to log in again.
Your QuickBooks account is now connected and you will be returned to XPS. Your orders will start syncing and will appear in the shipping area momentarily. To confirm you are connected, you should see "Connected" with the number of pending orders ready to be shipped at the top of the QuickBooks Online Integration Setup.