Do not leave bad criticism if you find any errors contact Discord and I will try to fix it.
Separate World Items, want to create a Network or a Server with various modes and separate its Inventories by worlds?, Separe World Items is what you need.
Version 2.0.0 is closer than ever, so version 1.0.0 will no longer be maintained. The code is now more optimized and friendlier for other developers to use its API.