I’ve been looking at this app, https://apps.shopify.com/shipping-rate-calendar, which shows a calendar on the second step of the checkout.
I’d like to implement something like this on a store I’m working with (this app doesn’t meet all their requirements), but I can’t seem to see the API that would allow me to insert user-interface elements at this step.
I can see the shipping rate scripts that allow me to update the shipping options that appear, but as I understand it they are limited in what they can do on that page.
Can someone point me in the right direction as to where I might be able to achieve something like this? Thanks.