Most of the items I have ordered from non-Aamazon small businesses during COVID-19 crisis is backed by Shopify platform. Their checkout form has a very unique layout so it is easy to tell without looking at the page source.
Many small Shopify retailers have pivoted quickly and are stocking some items that Amazon is having trouble keeping in stock.
I love that because my street name is like 40 characters long, it doesn’t even fit in the legacy IT systems used by utilities.