I did a lot of digging, and most of the things I come across are for versions older than 1.20.1
EntityEvents.spawned(event => {
let entity = event.entity
if (entity.type == "minecraft:piglin_brute" && Math.random() < 1.0) { //spawn chance with item
entity.mergeNbt(`{HandDropChances:[1.0f, 1.0f]}`) //drop chance
entity.setItemSlot(0, "simplyswords:soulstealer")}
})``` This is what I've got so far, no errors for my loot.js file in the logs. It just doesn't drop. The entity does spawn with it however.