Forum Academy Marketplace Showcase Pricing Features

Marketplace Database. Shipping costs

Hi! I’m doing a marketplace and I need that the user can change the shipping costs depending on the city, all for the same product. However, I don’t know how to save the database.
I tried using data type: shipping costs (list)
Fields: City, costs.
But I’m stuck on knowing how to assign a price to a city, having many cities and all within a same product.
I’ll like it to look like as in the picture.