How to properly set up AfterShip for Klaviyo and Shopify integration?

Hi, I just started a free trial with AfterShip in order to accomplish some delivery triggered email needs for my business through Klaviyo (and will upgrade to a paid plan once that is over).

A couple of questions… beyond having the App installed and integrated with Klaviyo, is there additional setup I need to do to integrate with my Shopify shipping and tracking? Or once the App is added to Shopify, does it just automatically connect and track shipments?

Also, there’s a place on AfterShip where you select your carrier – we always use USPS, but is it necessary to select that as our carrier, or is that just if you have a corporate account directly with USPS?

We’re going to do a test shipment today, but we want to make sure everything’s set up right before we do.

Thank you!