Open the downloaded ZIP product file and drop the folder in it somewhere in your resources folder. There is no key since this is free. Add start BigDaddy-PostalMap to your server.cfg.
IMPORTANT
By default this map has Prompt's Alamo Sea Bridge, Cayo Perico and Roxwood. To remove any or all of those read below.
By default it is WITH the Alamo Sea Bridge by Prompt. If you do not have that in your server, in the dev folder of the script is a stream folder with a version of the map without the bridge. Just copy the files in the dev stream folder into the main stream folder to have no bridge on your map. Be sure to back up the two files it will overwrite in case you get the bridge later. Or you could always download this again.
By default both Cayo Perico and Roxwood are turned on. To turn one or the other or both off, open the config.lua in the scripts folder and scroll to the bottom. There are four lines there with either --cayo or --roxwood next to them. For any you do not want in your map put -- (two dashes) in front of that line to comment it out.
NOTE
If you have Roxwood in and have the weird chunk of map that looks like it's just default map up on Roxwood, just delete this file in the Roxwood folder because it overrides everything: \amb-roxwood-map\stream\amb_rox_minimap\minimap_sea_0_0.ytd
There is a postals.json file in the dev folder that contains the postal data. It is based on the OCRP postals but the duplicates were fixed and new Roxwood and Cayo Perico postals were added. So replace your postals data file in your nearest postals script with this one to match. By default Roxwood and Cayo Perico are included and are marked with comments as to where they are in the file. Remove those sections if you do not have one or the other or both.
NOTE
If your nearest postal script doesn't like the comments and/or capital X and Y in the postals.json then use thepostals-luafriendly.jsonfile instead.
In the DEV folder are a bunch of FULLMAP**.png images that can be used for live maps. There is also a Sonoran Live Map in there that has the exact files you need to just upload into your Sonoran live map. Obviously if you have Roxwood and/or Cayo you just remove the -roxwood and/or -cayo in the names and use those files. There should be everything you need to setup your Sonoran live map in that folder.