How to implement a dynamic dropdown for shipping

Hi,

There is a lot of examples of product customization using custom fields but in the case where I want the user to select a delivery store with a dropdown in the shipping section, where should I put the (dynamic) data? The problem is that shipping methods are defined using the UI. I don’t have the equivalent of custom fields for shipping method.

I’m customizing “shipping-rates-list-item” in the snipcart-templates.html and I have:

Thanks.