Looking to remove default agreements from Wares, and replace them with custom ones.

This is a Modpack for the Wares Mod Intro: I'm currently trying to get my head around Data packs. I got it successfully loading into the game (according to the logs and /datapack list) but have little clue where to go from there. Where to go: I'm not sure where to go from here though. My suspicions are a combination of the loot table, and removing existing items by identifying them with their NBT tags? And then adding my own in their place. Not really sure though. Specifically, I am trying to remove the existing delivery agreements from the mod, and replace them with my own. Delivery agreements are items that contain requests for items, in exchange for other items. These are placed on a table with a cardboard box and the required items, and will be exchanged for the goods indicated on the delivery agreement. Delivery agreements have a set number of uses each. I'm uncertain where and how this information is stored. Research is under way.