In order to use this app your Shopify store plan must include access to the Carrier Calculated Shipping API
Yes. Your Shopify plan must include access to the Carrier Service API - the app can’t work without it. Just get in touch with Shopify. They’ll add it to your plans for $19.99/month, and it’s free with an annual plan.
Yes indeed! Try Rates by Distance for Shopify free for 30 days, so you can check how the app suits your workflow and does what you need. Cancel within that time and you won’t be charged.
The app works everywhere that Shopify does.