Cagerium datapack loot tables

Hello, let me introduce myself. I would like to know how to create a datapack for this mod called Cagerium. You can find the mod at the following link: https://legacy.curseforge.com/minecraft/mc-mods/cagerium
This mod allows you to place a mob on a block, and when the mob dies, it will drop the items it normally would. If you place a chest nearby, you can collect the dropped items automatically. It's like a mini-farm. The creator mentioned that datapacks can be created to modify what the mobs drop.
I would like the cow, when placed on a block, to drop milk buckets, leather, and raw beef. Similarly, I'd like the chicken to drop eggs, feathers, and raw chicken.
Here's what the creator mentioned about custom loot tables:
"You can add custom loot tables to your entities via datapack in the data folder /cagerium/[entityid].json"
However, this information is a bit limited for me, as I don't have much knowledge in this area. Another user posted the following comment:
"Took me a while, but I finally got it working. In case anyone else is interested, the correct path for customizing isolated loot tables for this mod is: namespace/loot_tables/cagerium/entity.json"
If you could help me create a datapack for this mod, that would be fantastic! I'll assist in any way I can!