Just like the title states, I have a job to build an interactive zonal map for the US, and I have two websites as a reference. These two websites are so similar that it has to be a package at work here, most likely.
https://nitrologistics.com/tools/usps-zone-calculator
https://www.pirateship.com/usps/zone-map
Please how do I go about building the exact replica of the map found in these websites?