Sandbox Square Gateway not working?


I am trying to sandbox the Square Payment Gateway with Alidropship plugin as the final thing to do before posting products but I am getting errors at the order submission. I have copied and pasted the sandbox credentials and used the Testing Sandbox credit cards to process an order but I still get "Request not authorized" when I submit an order.

I heard you get this error when the keys dont match but they do.. What I have tried:
- Following the Square setup guide
- I have re-copied+pasted the Square App ID / Secret Key to the payment options
- I toggled between USD and CAD currencies with valid postal codes
- I am using the latest Square API version but I have also tried each release for the last year and still the same response.

This is fresh installation of the latest wordpress/alidropship plugin. I would prefer not signing up for another payment gateway.

Square Testing values -

Please assist

Thank you,