Nearby (unrelated to this extension, AFAICT) is a company that creates a unified online storefront for local shops and they handle the separate ordering, pickup, and delivery to shoppers:

“On Nearby, they shop across multiple local stores, in one basket, with one checkout, and no fuss. After a customer checks out, we place orders with you and the other stores, and do the work of putting the order together.”

https://nearbyhq.com/