To resolve the error "Invalid auth/bad request (got a 403, expected HTTP/1.1 20X or a redirect)" in your Etsy Integration, follow the steps below.
Click this link: https://www.etsy.com/your/apps
This will bring you directly to your Etsy Store Apps page.
**You may need to log in to your Etsy store.
Select the “X” next to "eCommerce Webship”.
A pop-up window will ask you to confirm you would like to remove the app, select “Remove”.
A box will appear confirming it has been removed.
Return to the Etsy Integration settings in XPS Ship, and select Reconnect Integration”.
You will be redirected to Etsy’s website. You’ll be asked to allow our application to connect to your account. Select "Allow Access".
You will be redirected back to XPS Ship. At the top of the page, you will see that the integration is now connected.