There are 2 ways to check to see if the settings and the app itself is working:
Using the "Checkout test" feature within easyRates
Adding a product to the cart on your store and going to the checkout screen
To see how to use the "Checkout test" feature, please refer to the article here.
Examine how it will look from the customer’s perspective and check for mistakes or anything wrong with the checkout.
Go to your own Shopify store and access the checkout page with an item inside the cart.
Choose the country that you would like to check and insert the address.
(Make sure that the postal code/ zip code is something that exists.)
If the settings are set correctly, the changes you have made on easyRates will be displayed here.